Trying to change my profile picture back to the default initials have tried and no success

Hi! Are you referring to your RingCentral app?

This is your best option afaik...
https://ui-avatars.com/

Here is an example
https://ui-avatars.com/api/?name=Chuck+Strand&background=0D8ABC&color=fff&rounded=true&bold=true&size=300&font-size=0.70

In this 2nd link you can identify several keywords:
name=Chuck+Strand
background=0D8ABC
color=fff
rounded=true
bold=true
size=300
font-size=0.70

you can edit those to be whatever you want. For colors you can find the codes using this HTML color code picker https://html-color-codes.info/
For font-size use anything between 0.01 and 1.00.

There was a much more convenient app but, unfortunately it is down. RingCentral does not offer a way to revert the profile pic. I've searched a lot about this a few months ago :D