If you can’t download Subterbaldi mod menu I will tell you here

There are reasons why it may not install on your phone.  Reasons:  Your phone may not have enough storage space.  Try deleting some undeleted files or unneeded games.  It may be incompatible with your phone.  Try using another phone. If that doesn't work, try installing an older version. If that doesn't work, consider buying a new phone in the future.