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You can use a block element – hook, add a query loop block to it, set location to posts > all posts, selectafter_main_content hook.

For more hook locations, please check this:https://docs.generatepress.com/article/hooks-visual-guide/

Try pasting this into the Block Element as Ying mentioned:

<!-- wp:generateblocks/query-loop {"uniqueId":"713c981c","query":{"post_type":"post"}} -->
<!-- wp:generateblocks/grid {"uniqueId":"51823f02","columns":1,"horizontalGap":20,"verticalGap":20,"isDynamic":true,"blockVersion":3,"isQueryLoop":true,"lock":{"remove":true}} -->
<!-- wp:generateblocks/container {"uniqueId":"8e0ed88d","isGrid":true,"isQueryLoopItem":true,"gridId":"51823f02","backgroundColor":"#fafafa","isDynamic":true,"blockVersion":4,"sizing":{"width":"25%","widthMobile":"100%"},"spacing":{"paddingTop":"20px","paddingRight":"20px","paddingBottom":"20px","paddingLeft":"20px"},"lock":{"remove":true,"move":true}} -->
<!-- wp:generateblocks/image {"uniqueId":"9dbd9267","sizeSlug":"full","blockVersion":2,"spacing":{"marginBottom":"30px"},"useDynamicData":true,"dynamicContentType":"featured-image"} /-->

<!-- wp:generateblocks/headline {"uniqueId":"213247fc","element":"p","blockVersion":3,"typography":{"fontSize":"14px"},"spacing":{"marginBottom":"30px"},"dynamicContentType":"post-date","className":"dynamic-term-class","gpDynamicTextType":"terms","gpDynamicTextReplace":"Terms","gpDynamicTextTaxonomy":"category"} -->
<p class="gb-headline gb-headline-213247fc gb-headline-text dynamic-term-class">Terms</p>
<!-- /wp:generateblocks/headline -->

<!-- wp:generateblocks/headline {"uniqueId":"0506374e","blockVersion":3,"typography":{"fontSize":"30px"},"spacing":{"marginBottom":"5px"},"useDynamicData":true,"dynamicContentType":"post-title","dynamicLinkType":"single-post"} -->
<h2 class="gb-headline gb-headline-0506374e gb-headline-text"></h2>
<!-- /wp:generateblocks/headline -->

<!-- wp:generateblocks/headline {"uniqueId":"47655257","element":"div","blockVersion":3,"dynamicContentType":"post-excerpt","className":"","gpDynamicTextType":"user-meta","gpDynamicLinkType":"author-archives","gpDynamicTextReplace":"User meta","gpDynamicTextBefore":"By "} -->
<div class="gb-headline gb-headline-47655257 gb-headline-text">User meta</div>
<!-- /wp:generateblocks/headline -->
<!-- /wp:generateblocks/container -->
<!-- /wp:generateblocks/grid -->
<!-- /wp:generateblocks/query-loop -->

Could you please provide the link to the page section that you’ve completed?