Replace paths from URI

I want to rewrite

https://mydomain.com/app#/listClients?token=e34f14bae3fb68ecb042328f1b5a6d9

to

https://mynewdomain/new-path#/listClients?token=e34f14bae3fb68ecb042328f1b5a6d9

ie., I want to replace mydomain with mynewdomain and I want to replace app# with new-path#

I tried

rewrite ^/app#/(.*) https://mynewdoain.com/listClients#/$1 permanent;