On mobile, you can create it like this.
Create wallet.
Import Bitcoin addresses or private keys (because you want to create a watch-only wallet, after this step, you will import your Bitcoin address).
Paste your Bitcoin address.
Create your wallet password.
Finish.
Wait for syncing and see your wallet balance (watch only).
You do not import your private keys or seed phrase when creating a watch-only wallet, all you need when setting up a watch-only wallet on Electrum is your master public key. Import your MPK into the wallet and you can then watch all activities on your wallet from this watch-only device, but you cannot spend funds from it, neither can funds be stolen from it.