I’ve got the exact same problem and the following procedure has worked for me.

Just run the following commands in the below-given order:

gem list --local | grep cocoapods

sudo gem uninstall (each item from above command)

sudo rm -rf ~/.cocoapods

sudo gem install cocoapods

cd (PROJECT DIRECTORY)

pod init

(put cocoapod in podfile)

pod install

rm -rf ~/.cocoapods/repos/trunk/

pod cache clean --all

pod install

Reference Link :
Pod install failure – Catalina 10.15.3