Git Submodule update over https

Edit your .gitmodules file with the https url, for example:

[submodule "vendor/engines/fat_free_crm"]
    path = vendor/engines/fat_free_crm
    url = https://github.com/fatfreecrm/fat_free_crm.git

Then run git submodule sync to reflect the change to your .git/config file.

Credits: https://stackoverflow.com/a/6632693/1273077

In your .gitmodules file in the root of your repo, and in the .git/config file, you should find a section for your submodule. You can edit the url there so it is accessed via https request rather ssh.

Of course it may already be an ssh url, in which case the problem may be something else, but this is the first place to check.