Hi @ashf,
Thanks for your question. There are no filter or action hooks to override the Post Carousel block however you may override it by copying the following file
\wp-content\plugins\getwid\includes\templates\post-carousel\post.php
and paste it to your theme folder with the following directory structure
\wp-content\themes\ %active-theme% \getwid\post-carousel\post.php
Note: you may also create your custom Post Template for Carousel where you may add Custom Fields block if you wish to show some https://prntscr.com/1175t3w