As with other smart contract wallets, multisig account must be deployed to be able to transact.
First, the account needs to be funded (with ETH or STRK) before a transaction is possible. You can topup your multisig account by clicking Fund on the home page.
Your multisig wallet will be automatically deployed within the first outgoing transaction, for example, a swap or a simple transfer.
You can also activate (deploy) the account by clicking Activate multisig once the account has funds in it:
Account activation is an on-chain transaction, it has a small network fee on it and can only be initiated by the account creator, not the co-signers. It might take a few minutes to complete on-chain.