Help with custom variables

We at the USA TODAY NETWORK leverage customized WordPress block editor for our CMS’ story editor and as part of that, we are looking to see if can leverage the Yoast plugin for SEO.
We have our custom SEO fields (stored in the wp_postmeta table) that we are looking to send into Yoast’s SEO Title – either as a custom field or returning custom data for an existing field), so that the preview on the post edit page displays it appropriately.

I have tried both things using the code snippets suggested at https://gist.github.com/amboutwe/550c10ede7d065d9264930f5480ca748#file-yoast_seo_title_custom-variable-php, without luck. See screenshot below for what displays in the editor (myname is a custom variable, and I have a filter to display custom content for the native title variable).

I am not seeing the “Custom fields input box” mentioned in this article https://yoast.com/help/add-custom-fields-to-yoast-seo-premium-plugin-settings/, but I was able to inject custom variables directly into the wp_options table for option name wpseo_tables like so (see value for title-post)

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a:107:{s:17:"forcerewritetitle";b:0;s:9:"separator";s:5:"sc-gt";s:16:"title-home-wpseo";s:40:"%%myname%% %%page%% %%sep%% %%sitedesc%%";s:18:"title-author-wpseo";s:41:"%%name%%, Author at %%sitename%% %%page%%";s:19:"title-archive-wpseo";s:38:"%%date%% %%page%% %%sep%% %%sitename%%";s:18:"title-search-wpseo";s:63:"You searched for %%searchphrase%% %%page%% %%sep%% %%sitename%%";s:15:"title-404-wpseo";s:35:"Page not found %%sep%% %%sitename%%";s:25:"social-title-author-wpseo";s:8:"%%name%%";s:26:"social-title-archive-wpseo";s:8:"%%date%%";s:31:"social-description-author-wpseo";s:0:"";s:32:"social-description-archive-wpseo";s:0:"";s:29:"social-image-url-author-wpseo";s:0:"";s:30:"social-image-url-archive-wpseo";s:0:"";s:28:"social-image-id-author-wpseo";i:0;s:29:"social-image-id-archive-wpseo";i:0;s:19:"metadesc-home-wpseo";s:12:"%%sitedesc%%";s:21:"metadesc-author-wpseo";s:0:"";s:22:"metadesc-archive-wpseo";s:0:"";s:9:"rssbefore";s:0:"";s:8:"rssafter";s:53:"The post %%POSTLINK%% appeared first on %%BLOGLINK%%.";s:20:"noindex-author-wpseo";b:0;s:28:"noindex-author-noposts-wpseo";b:1;s:21:"noindex-archive-wpseo";b:1;s:14:"disable-author";b:0;s:12:"disable-date";b:0;s:19:"disable-post_format";b:0;s:18:"disable-attachment";b:1;s:20:"breadcrumbs-404crumb";s:25:"Error 404: Page not found";s:29:"breadcrumbs-display-blog-page";b:0;s:20:"breadcrumbs-boldlast";b:0;s:25:"breadcrumbs-archiveprefix";s:12:"Archives for";s:18:"breadcrumbs-enable";b:1;s:16:"breadcrumbs-home";s:4:"Home";s:18:"breadcrumbs-prefix";s:0:"";s:24:"breadcrumbs-searchprefix";s:16:"You searched for";s:15:"breadcrumbs-sep";s:2:"?";s:12:"website_name";s:0:"";s:11:"person_name";s:0:"";s:11:"person_logo";s:0:"";s:22:"alternate_website_name";s:0:"";s:12:"company_logo";s:0:"";s:12:"company_name";s:0:"";s:17:"company_or_person";s:7:"company";s:25:"company_or_person_user_id";b:0;s:17:"stripcategorybase";b:0;s:26:"open_graph_frontpage_title";s:12:"%%sitename%%";s:25:"open_graph_frontpage_desc";s:0:"";s:26:"open_graph_frontpage_image";s:0:"";s:10:"title-post";s:37:"%%title%% %%page%% %%sep%% %%myname%%";s:13:"metadesc-post";s:0:"";s:12:"noindex-post";b:0;s:23:"display-metabox-pt-post";b:1;s:23:"post_types-post-maintax";i:0;s:21:"schema-page-type-post";s:7:"WebPage";s:24:"schema-article-type-post";s:7:"Article";s:17:"social-title-post";s:9:"%%title%%";s:23:"social-description-post";s:0:"";s:21:"social-image-url-post";s:0:"";s:20:"social-image-id-post";i:0;s:10:"title-page";s:39:"%%title%% %%page%% %%sep%% %%sitename%%";s:13:"metadesc-page";s:0:"";s:12:"noindex-page";b:0;s:23:"display-metabox-pt-page";b:1;s:23:"post_types-page-maintax";s:1:"0";s:21:"schema-page-type-page";s:7:"WebPage";s:24:"schema-article-type-page";s:4:"None";s:17:"social-title-page";s:9:"%%title%%";s:23:"social-description-page";s:0:"";s:21:"social-image-url-page";s:0:"";s:20:"social-image-id-page";i:0;s:16:"title-attachment";s:39:"%%title%% %%page%% %%sep%% %%sitename%%";s:19:"metadesc-attachment";s:0:"";s:18:"noindex-attachment";b:0;s:29:"display-metabox-pt-attachment";b:1;s:29:"post_types-attachment-maintax";s:1:"0";s:27:"schema-page-type-attachment";s:7:"WebPage";s:30:"schema-article-type-attachment";s:4:"None";s:18:"title-tax-category";s:53:"%%term_title%% Archives %%page%% %%sep%% %%sitename%%";s:21:"metadesc-tax-category";s:0:"";s:28:"display-metabox-tax-category";b:1;s:20:"noindex-tax-category";b:0;s:25:"social-title-tax-category";s:23:"%%term_title%% Archives";s:31:"social-description-tax-category";s:0:"";s:29:"social-image-url-tax-category";s:0:"";s:28:"social-image-id-tax-category";i:0;s:18:"title-tax-post_tag";s:53:"%%term_title%% Archives %%page%% %%sep%% %%sitename%%";s:21:"metadesc-tax-post_tag";s:0:"";s:28:"display-metabox-tax-post_tag";b:1;s:20:"noindex-tax-post_tag";b:0;s:25:"social-title-tax-post_tag";s:23:"%%term_title%% Archives";s:31:"social-description-tax-post_tag";s:0:"";s:29:"social-image-url-tax-post_tag";s:0:"";s:28:"social-image-id-tax-post_tag";i:0;s:21:"title-tax-post_format";s:53:"%%term_title%% Archives %%page%% %%sep%% %%sitename%%";s:24:"metadesc-tax-post_format";s:0:"";s:31:"display-metabox-tax-post_format";b:0;s:23:"noindex-tax-post_format";b:1;s:28:"social-title-tax-post_format";s:23:"%%term_title%% Archives";s:34:"social-description-tax-post_format";s:0:"";s:32:"social-image-url-tax-post_format";s:0:"";s:31:"social-image-id-tax-post_format";i:0;s:14:"person_logo_id";i:0;s:15:"company_logo_id";i:0;s:29:"open_graph_frontpage_image_id";i:0;s:26:"taxonomy-category-ptparent";s:1:"0";s:26:"taxonomy-post_tag-ptparent";s:1:"0";s:29:"taxonomy-post_format-ptparent";s:1:"0";}
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Is there something I am missing?

Thanks.

Binita