featured image problem

heey guys i recently installed the collection 1.0 on my wordpress. but, the only problem is i can’t get it to show the featured image after setting it. after a lot of time looking up in the net i finally got it to show the featured image on the index but it doesn’t show correctly as it shows in between the post and not in the post itself.

anyway here’s my site : https://hqsharewld.co.nf/

can u guys plz give me suggestions. i declared the function in functions.php and added the code to the loop in addition to other things ive done that i can’t remember because of the fact that i’m not good with php coding.

And i also got the image to show in another theme called mixfolio but the problem is that it’s showing up too small , here have a look guys and tell me what you guys think https://hqsharewld.co.nf/?preview=1&template=mixfolio&stylesheet=mixfolio&preview_iframe=1&TB_iframe=true