Code for changing header of blog post

Hi,

I’ve been busy setting up my website in wallstreet theme for a while now and now finally the time has come to write some blog posts. I wasn’t able to change the header image of individual blog posts though. I had the same problem with pages and categories but using this code, that was no longer an issue:

.page-id-‘idnumber of page’.page-mycarousel {
background: url(‘link to photo’) repeat scroll 0 0 / cover #143745 !important;
box-shadow: 0 7px 10px -10px #000;
padding: 336px 0 65px;
}

.category-‘idnumber of category’.page-mycarousel {
background: url(‘link to photo’) repeat scroll 0 0 / cover #143745 !important;
box-shadow: 0 7px 10px -10px #000;
padding: 336px 0 65px;
}
.page-mycarousel img
{
display:none !important;
}

I was hoping a similar code would exist for changing the headers of individual blog posts. I have not been able to find it online, I hope someone can help me with the right code.

Thanks!