Mongodb backup and restore from 2.6 to 6 in Ubuntu 20.0

I am trying to restore admin db from mongodb version 2.6 to 6 in ubuntu 20 and have used following commands, but still facing error

commands used
mongodump --out /commvault

mongorestore /commvault

mongodump -u xxxx -d admin -c system.users -p xxx -v --authenticationDatabase admin -o systemusers.bson &> xxx_dump_date “+%Y-%m-%d”_backupoutput.log

mongorestore -d admin -c system.users -u “xxxx” -p “xxxx” -v --authenticationDatabase “admin” system.users.bson &> xxxx_bsonoutput_dec7.log

for admin db backup

mongodump --collection=myCollection --db=test

**Failed: the users and roles collections in the dump have an incompatible auth version with target server: cannot restore users of auth version 1 to a server of auth version 5**

Still not able to resolve . Please let me know feasible solution