Elementor is not very automation friendly, you can only do it via the database and that’s ugly.
BUT, you could add ACF fields for those titles, buttons etc and use Elementor Pro’s Dynamic Tags.
Simple fields can be managed with the make.com plugin. It has a „Custom fields“ setting.
For more advanced fields like repeater you need to install the plugin „ACF to REST API“ and than you could update the posts via the REST API like:
POST /wp-json/acf/v3/{post_type}/{post_id}
but its more complicated.