Do I have to file form 8938 have only signatory authority over accounts in Canada (aunt's bank accts)

I am an American citizen who lives in NY. My aunt is a Canadian resident and citizen. She is elderly, and needed help with her finances. We went to her bank and I obtained signatory authority over her accounts. She is the owner of all the funds in the accounts. She pays taxes on all the income earned. I help her manage. Do I have to file Form 8938 as I do not own any accounts, just help her pay bills, etc.

I know I have to file the FBar form. That I understand. Confused on the 8938 form.