Hi, to change the layout of gallery slider you have to override template. Template files can be found within the /essential-real-estate/public/templates/ directory. You can edit these files in an upgrade-safe way using overrides. Copy it into a directory within your theme named /ere-templates/, keeping the same file structure but removing the /public/templates/ subdirectory.
Example: To override the contact agent in single property page, copy: wp-content/plugins/essential-real-estate/public/templates/single-property/contact-agent.php to wp-content/themes/yourtheme/ere-templates/single-property/contact-agent.php
The copied file will now override the essential-real-estate default template file.
Note: Do not edit these files within the core plugin itself as they are overwritten during the upgrade process and any customizations will be lost.