Error on adding new ssh key to keystore: msg="illegal base64 data at input byte 49"

While adding a new ssh key to key store got "Request failed with status code 400" in modal window "New Key".

Semaphore version: v2.9.64
docker image: semaphoreui/semaphore:latest (c0068bfcb298)
use both nginx proxy and direct on :3000 port

Key name: k1
Type: SSH Key
Private key: tried both ed25519 and RSA

