Selling through TPT

Hello,

I'm in desperate need of someone with some instgram/facebook business knowledge. I am an elementary school teacher that sells resources online through a third-party site www.teacherspayteachers.com. I was able to create a facebook shop page but for whatever reason my instagram request keeps getting rejected.

It tells me that I need to verify the domain, which is fine, but I am unable to access TPT's DNS or HTML file.

How do I set up my instagram shop if I am selling my products through a third-party site?

Any suggestions is very much appreciated. I wouldn't mind receiving an e-mail, explaining what it is I should be doing.

Thanks in advance.