Once you start tasks, you will be prompted to choose which stage of the run to drop for.
Magic Eden Ordinals stage selection
Address Derivation
Magic Eden Launchpad accepts all sorts of wallet types to pay: Taproot, Native Segwit, Nested Segwit, etc.
In the case that the wallet you have was whitelisted through another method different from Taproot, you can try to use Native Segwit or Nested Segwit addresses for source of payment. The Ordinal asset will be received on your Taproot address nevertheless, as it's the only one which actually has support for them.