authenticaion failed (could not find any suitable RSA key to authenticate with)

[anta40]

I misconfigured my old VPS, so wiped it and created a new one.

SCP using SSH key works fine (tested with Termius) :

• Put the public key on VPS
• Provide the private key to Termius (no need to copy paste the content, just input the file path)
• Done. Making directory, copying files etc work fine.

Now let's configure termscp again (I'm using v0.13.0 on macOS Monterey x64):

1. Open configuration menu, go to "SSH keys tab", remove all existing keys and provide a new one, like this: hostname = my VPS public IP. username = anta40.
2. nvim shows up, asking for the private key. I copy pasted it, make sure it's indeed the appropriate private key, no typo etc and save it
3. On termscp main menu, create the connection: protocol = SCP, remote host = VPS public IP, port number = 22, username = anta40. No password (blank).
4. Prese Enter. Got this: authenticaion failed (could not find any suitable RSA key to authenticate with)

What's wrong here?