A transaction hash is a unique identifier for every transaction recorded on the blockchain. People use these to find details regarding a specific transaction or transfer.
If you just made a withdrawal, the View on Solscan or View on block explorer link the app shows when it completes opens the transaction directly. Otherwise, here is how to navigate:
Copy your wallet address
Start by copying your wallet address from fomo. On the mobile app, open the Portfolio tab (its icon is your avatar), tap the gear icon to open Settings, then Profile and Account, and tap the addresses row to expand it. On the web app, open your account menu, then Manage account.
You will see your Solana address and one row per EVM network, and every EVM row shows the same address. Tap the one that matches the network of the transaction you are looking for; tapping copies it.
Where the hash is on each explorer
Paste your wallet address into the search bar of the blockchain explorer for that network. This will load your account page. Here is where to go and what to look for on each network:
For Solana, use solscan.io. Select the Transfers tab. The hash is in the Signature column.
For Base, use basescan.org. Select the Token Transfers (ERC-20) tab. The hash is in the Transaction Hash column.
For BNB Chain, use bscscan.com. Select the Token Transfers (BEP-20) tab. The hash is in the Transaction Hash column.
For Monad, use monadvision.com. Open the Activity tab. The hash is in the Txns column.
For Robinhood Chain, use robinhoodchain.blockscout.com. Paste your address and open the token transfers view to find the transaction.
For Ethereum, use etherscan.io. Select the Token Transfers (ERC-20) tab. The hash is in the Transaction Hash column.
For Arc, use explorer.arc.io. Paste your address and open the token transfers view to find the transaction.
Transactions settle as transfers, so this is the easier tab to navigate to find what you are looking for. Find the transfer you are looking for by matching the time, amount, and token. Each hash has a copy icon next to it that copies the entire unique transaction hash.