Query Loop Block - Insert block after so many post

[TheAggressive]

Hello,

Im wondering how I could go about adding a block after so many post and continue with the loop. I know how to in the classic way of the loop but not sure how to go about it in a block theme type of way. Something like:

Post 1
Post 2
<-- Inserted Block -->
Post 3
Post 4

<-- Pagination here -->

Any help or guideness is appreacited!

Thank you!