How to submit a complex extrinsic with Multix
If Multix interface doesn't allow you to craft a manual transaction as complex as you want. There is still a way to make your life easier.
Multix allows you to import an extrinsic that you have created on Polkadot.js/apps and it will automatically take care of wrapping it with the multisig and eventually proxy. Also thanks to the way Multix works, the signatories will be able to review the call. Here is how it goes:
Note that you do not need to care about the sender here you can use any account.
Head to Polkadot.js.org/apps > Developer > Extrinsics and craft your transaction. E.g if you want to create a batch, you can do it directly. Again, there is absolutely no need to mention the multisig, a proxy or anything. Just focus on the call you want to make.
This call data is the information about the call itself, it does not contain the sender. Make sure to copy the "encoded call data", not the encoded call hash.
Go to Multix. Make sure you have selected the right network and multisig account you want to make this call from.
Click on "New Transaction"
Select in transaction type: "From call data"
Then you can paste the call data that you copied earlier. This call will be decoded.
Make sure to select the correct proxy/multisig and signatory that you want to send your transaction with. Multix will make sure to wrap your call with the right multisig/proxy call.
You can now send it, it will appear in a few second and other signatories will be able to review it.