Convert multi-line ssh public key to one-line for .ssh/authorized_keys

I received a public key like this and I should add it to .ssh/authorized_keys:

---- BEGIN SSH2 PUBLIC KEY ---- Comment: "rsa-key-20190107" AAAAB3NzaC1yc2EAAAABJQAAAQEAucNIPbPoaEqyBAKtk3LTfM/hiZlWomTdQEf7 zUI4LGz91aZYIZNpWGTAUZKuFLdIEsktxQTNwEJNWMe2QocqQWyPGA+xL08ZP7Xk VEbVOyH0nQ3ZHptgmyH4y4+bbAWXAROL3078h2iwtsCO343VQKg1iSNvemnLafA5 9/RtkcCR8SxH+NEXcc8MwGOE9gLX2pph4bxrFz9R6yyw3oRGVLt4uU9BlD3+LXg1 plUzc2KZXEt8Zr04I0Fd865zyiB8Q+2ZEPvHf7MMaW66FRe4BXCI7LMh/voXi0C8 H4NDIu1GZr7dNxgbEO05ZnASMofpLDU6cq7LFVl0BQG8gt1hOw== ---- END SSH2 PUBLIC KEY ---- 

I guess that I can edit this file in vi and to create the corresponding one-liner which is required for .ssh/authorized_keys.

Is this true?

AFAIK this key was created according to this page: https://winscp.net/eng/docs/guide_public_key