Atomic transaction without memo

I sent a transaction from my Keplr wallet to an exchange address but did not include the memo, and unfortunately the funds have not arrived yet. My exchange told me that they do not see any deposit. What should I do now?

The exchange has your funds. They usually use one deposit address and distinguish user deposits by memos. So only the exchange can do anything about it - just explain to them that you forgot to include memo, if they have a procedure for this kind of situation - they should let you know your next steps.

Thank you. I provided them with the explorer link, but they say that the link shows a ‘transaction not found’ error. Is this possible?

Can you see the transaction yourself on mintscan for example? If yes - the exchange support is either incompetent or up to something. You can try giving them a direct transaction link, such as https://rest.cosmos.directory/cosmoshub/cosmos/tx/v1beta1/txs/<TX_HASH>

Ok. Besides the link, the hash, the sending and receiving address, what are other important details to provide to the exchange support to locate my funds?

Different exchanges can have different rules, so only they can tell you that. Successful deposit transaction proves that deposit happened and they have the funds now. They probably will want some sort of proof that sending address belongs to you, so just talk to them about their process.

Thank you very much, you have been very kind