Cannot redeclare myplugin_update_db_check()

I get this error:

PHP Fatal error: Cannot redeclare myplugin_update_db_check() (previously declared in /wp-content/plugins/header-footer-code-manager/99robots-header-footer-code-manager.php:61

I think you need to rename that function and the call for it, the name you using is taken from an example code, others might use it and it gives an error 500 that crashes the site.

I renamed it like this on row 60
function robots_header_footer_code_manager_update_db_check() {...

And this on row 91
add_action( 'plugins_loaded', 'robots_header_footer_code_manager_update_db_check' );