You do not have permission to access \\server\folder name. Contact your server administrator to request access.
How to force Windows to prompt for credentials while accessing share
Then delete the conflicting share with;
NET USE \\server\share /DELETE
Finally, using the accepted answer will succeed;
NET USE \\servershare /u:USERNAME
Enter the password for 'USERNAME' to connect to 'SERVERNAME':Network@123
The command completed successfully.
How to force Windows to prompt for credentials while accessing share
Then delete the conflicting share with;
NET USE \\server\share /DELETE
Finally, using the accepted answer will succeed;
NET USE \\servershare /u:USERNAME
Enter the password for 'USERNAME' to connect to 'SERVERNAME':Network@123
The command completed successfully.