If you encounter difficulties using the PASTE function on your Android device, the easiest way to solve this is to install a keyboard with the Paste function already built into the keyboard.
There are many keyboards Apps available in Google Play. Below is an example using Gboard.
Step 1
COPY the text that you wish to paste
Step 2
Open and proceed as usual. Once you are ready to PASTE, below are the step-by-step screenshots.
Note that there might be some variations between different device models.
Step-by-Step Screenshots