Thank you all for your help. Unfortunately, I forgot to ask an important question in my first post:

Can the task of signing a message with my address - so that I can prove I am the owner of a transaction - be done
after the transaction has taken place? For example, if the recipient complains a week later that I am not the person
who initiated the transaction, can I still sign a message at that point?

Please note that I am using Electrum on Tails without persistence, so I would need to recover my Electrum wallet
from the seed.


Thank you!