Why is the Encrypt Wallet option in my Swing wallet disabled?
Is there any possibility to set a wallet password in "Eleos for Zlassic" ?
I can't find it.
You mean for wallet encryption? AFAIK it is not yet possible. See (e.g.):
https://z.cash/blog/new-release-candidate-less-than-one-week.html (should be the same for zclassic/zencash):
Wallet encryption has been disabled. The reasons for disabling this feature for the time being are explained in our security warnings document. We recommend using full disk encryption for now instead.