Q: why is apple ID disabled on phone  it's fine on the computer

Is it the same Apple ID that you're logging in on both devices?

If your Apple ID is locked or disabled:

https://support.apple.com/en-us/HT204106

Even though it works on the computer, follow the instructions for resetting your Apple ID password here >  If you forgot your Apple ID password - Apple Support

Then try your iPhone.

You may have an iTunes billing issue. You must call Apple Support to resolve this.

OK... there is no other explanation for what you are seeing.

Getting on the site is NOT related to having a billing issue. Not being able to update apps is.

Have you checked with iTunes? Humour me.