How do I get rid of this box?

Hi,

I'm a novice in WordPress, but I need help resolving an issue. How do I get rid of this white box with a donation form link? Any help is appreciated. Thanks.

Edit: the box used to have a donation form. i got rid of the form but can't get rid of the box.

https://preview.redd.it/nzs3nk36p7rd1.png?width=664&format=png&auto=webp&s=96f649c633630de9b62dfe37d10947db4473767a