How the approval is handle in SNS?

based on this I could make an upgrade propsal. But it does not show how the upgrade approval works? or is there approval at all?

So for example, can I call `dfx canister call sns_root voit “(myid, up)” then when voting up is 55% the proposal will be approved? or how it is working ?

Proposals are executed when >50% of the votes approve, or when the voting time expires and the majority (needs to be at least 3% in favour) approves. I don’t know where these parameters are documented