Today I was playing around with embedding text on the block chain, I found several tutorials using My Ether Wallet but they seemed out of date, and the browser kept crashing on the send.
Finally found a way that works using MetaMask and MyCrypto.
Your text first needs to be transferred from text form to hex format, for this I used this online editor from Online-Toolz but you can use any editor you want.
You will also need some Ethereum coin, again - you can get this wherever you want. I happen to use coinbase but again whatever exchange you prefer.
These were preformed on a Chrome browser - and worked as of Nov 2020.
1) MyCrypto https://mycrypto.com/account/send
2) Choose the Web3 "Connect & Sign via your browser extension)
3) If you do not have the Metamask extension, MyCrypto gives you a handy link to downloads it
4) Setup your MetaMask Wallet if you don't have one (again read the starting intro on safety - it is important)
5) Send Ethereum to your MetaMask wallet if you don't have any yet.
6) Login to MyCrypto, you should get a message confirming form the browser extension
7) Choose the option 'Send' Ehter & Tokens
8) Paste your send address (it can be any valid address you want it will be for
9) Sent the amount to send to zero (however it will still cost coin "GAS" in order to embed the data)
10) Expand the "+Advanced Box"
11) Enter the Hex Data in the data section (you may get a message that you a warning that you are sending a 'non-standard' transaction.
12) Hit Send
13) Watch for a 'confirm' button on the left hand side of your browser, this is your MetaMask extension confirming the transaction
14) Hit CONFIRM
You should see links to verify the transaction on the blockchain. Copy these TX addresses, they will let you see the 'hidden' message