How to sign a message?!

[Cantsay]

Code:

-----BEGIN BITCOIN SIGNED MESSAGE-----
Thank you Shorena for the great tutorial, I'm signing this message to show that I didn't only just look at the post but also learnt something from it. 
-----BEGIN BITCOIN SIGNATURE-----
Version: Bitcoin-qt (1.0)
Address: 1Ex3cMqXFAnjPi6T6SEySF37Pvu3172bkh

IIX+WViyUfeFDIh+XyI1V3NkNAlw9HPGBATNlcpFh2iaW/2WzSZHftRJTDF7JIHYcnlvBRd86GFFGHgRJmNohcg=
-----END BITCOIN SIGNATURE-----

Edit:

It looks like he accidentally added a single whitespace at the end of the message (after the dot

Thanks for spotting the error, I have corrected and verified it with mycelium wallet. But I will still appreciate if you can also verify the message for me.

[SFR10]

~Snipped~

It seems that something is wrong with your signed message ^{[e.g. it could be an extra space or something like that]}... I had no luck in verifying it with Bitcoin Core, Trezor Suite, Electrum, and Brainwallet!
^{- Sign another message and check if you can verify it on "Brainwallet".}
You might want to sign a message on the following thread as well: Stake your Bitcoin address here

Update:

It looks like he accidentally added a single whitespace at the end of the message (after the dot) but omitted it in that reply.
But it can't be verified by any tool aside from Brainwallet's Verify Message - Bitcoin-QT tab and manually adding the "space".

Great catch

[nc50lc]

~Snipped~

It seems that something is wrong with your signed message ^{[e.g. it could be an extra space or something like that]}... I had no luck in verifying it with Bitcoin Core, Trezor Suite, Electrum, and -snip-

It looks like he accidentally added a single whitespace at the end of the message (after the dot) but omitted it in that reply.
But it can't be verified by any tool aside from Brainwallet's Verify Message - Bitcoin-QT tab and manually adding the "space".

His signed message in this board can be verified though: /index.php?topic=5300698.msg60497828#msg60497828

[Linklord]

-----BEGIN BITCOIN SIGNED MESSAGE-----
I'm Linklord, today is 2023.02.26. I sign this message for my account
-----BEGIN SIGNATURE-----
bc1qqct2sqfskkgnscxjgg4zk6p6x3r9jpj7ctxkvx
Hw5vbnC+hssLCKYNjLfD3aZuonhAdZtzue1t5EPPpoyKA0erBjioCnWucKeTgQnduvguECpVVoSMBaOnstmWbzM=
-----END BITCOIN SIGNED MESSAGE-----

[Coiningking]

Is there an alternative I can use to sign a message since coinbase doesn't let you?

All previous transactions were on coinbase..

[_act_]

Is there an alternative I can use to sign a message since coinbase doesn't let you?

All previous transactions were on coinbase..

You can not sign a message on an exchange or custodial wallet. Also you can not sign a message with an address that an exchange or custodial will generate you.

Are you talking about the Coinbase noncustodial wallet? Import the seed phrase on Electrum, Sparrow or Bluewallet wallet and sign the message from any of the wallet.

[Financisto]

OP maybe you should add this to your tutorial thread: 

BitcoinMessageTools: https://bitcoinmessage.tools

GitHub: https://github.com/shadowy-pycoder/BitcoinMessageTools

GitHub (CLI): https://github.com/shadowy-pycoder/bitcoin_message_tool

[LTU_btc]

OP maybe you should add this to your tutorial thread: 

BitcoinMessageTools: https://bitcoinmessage.tools

GitHub: https://github.com/shadowy-pycoder/BitcoinMessageTools

GitHub (CLI): https://github.com/shadowy-pycoder/bitcoin_message_tool

This thread was last updated back in 2018 and OP isn't active on Bitcointalk for several years already. It would be good to check outdated information, fix images and add new stuff, but it won't happen, unless someone will make new version of topic