Could someone help me find the solution?
I want to use localStorage instead of sessionStorage for torus iframe.
But, I don't know what param to pass to web3auth.init()
Are you using torus-embed? If so, the option is removed(The docs you are referring are old, Please refer to https://docs.web3auth.io. ). Right now default is sessionStorage for iframe from torus-embed.
If you are using torus wallet ui plugin, then there is no option to choose between localStorage and sessionStorage. Default is sessionStorage.