I can't seem to find where to add/update the logo for PayPal button checkout

[4everfitness]

I searched through the help but either the instructions were no longer correct (link doesn't exist) or it wasn't relevant to my situation.

Go to https://www.4everfitness24.com/sign-up-thank-you.htm

Click on the top subscribe button.  When the PayPal screen comes up, the logo at the top is not showing up.  I want to change this but I can't figure out how.  Please help.