Alby allows you to store several Nostr private keys and to switch between them. But you need to add an account for each of them. It could be an Alby account or another lightning node/wallet.
Happy to help with the setup.
Discussion
Thanks. I wanted several nostr accounts within the same Alby account. But duplicating the lndhub connection string seems to work, I have 2 different accounts with the same LN node but different nsecs