Where are you located? It is almost always the case that bank accounts section isn't there because you are not in a supported country where Square offers Credit card processing.
Card payment acceptance with the Square app is currently available in the US, Canada, Japan, Australia, and the United Kingdom. We currently don’t support payment card processing outside of these countries or in U.S. territories such as Puerto Rico, Guam, the U.S. Virgin Islands, American Samoa, and Northern Mariana Islands.
