Some ideas -

 

1.  Using another device eg tablet, open your authenticator app (eg Authy) with your credentials and obtain the code

2.  Contact your Prompt Administrator or Prompt Support to reset the MFA, to enable you to use another device to set up MFA 

3.  If there is someone at home, perhaps they could tell you what the code is

 

Note: You could install the computer option to use as a back-up