lyngsat is missleading, it lists a few channels as free, but most of us assume free as in unencrypted. lyngsat assumes free as in zero monthly cost.
so there are two types of free.
fixed key and unencrypted. there is very little unencrypted. there is a little that is fixed key, when you sub an ird they send the keys for these channels, when you cancel its ok because they never ever change the keys so you can still watch these channels.
if you have an ird that can not be subbed, ie genpix, then you have no way of ever watching fixed key channels. if you have an ird that can be subbed but never has been, you'll have to sub it first.