First things first, install the Microsoft Edge app on your phone.
To get the Collabwriting mobile extension on Microsoft Edge, follow these steps:
Open the Edge menu: Click the button in the bottom right corner to open the menu.
Open the extensions list: In the menu, find the Extensions option.
Scroll down to Collabwriting: Scroll through the list of extensions until you find Collabwriting.
Note: This is only available to android users