chandrantwins on "[Plugin: Front-End Only Users] Translate message to deutsch"

Hi team,

Thanks for your good work..

I cannot translate this sentence to deutsch(german).

"There is already a user with that Useame, please select a different one."

I am not able to identify where i can modify this sentence to deutsch. Please help me regarding this.

https://wordpress.org/plugins/front-end-only-users/