I agree with jackthe hat.
I use Scotland's People all the time(I have Scottish Ancestry).
Like many such sites you pay for Credits,and use them up as you search,so you are not ties to an annual membership.
As Scotland's People's records are smaller than England's(due to the smaller population,in many cases you can read the certificates On~Line,(which you can't for England)and not pay large sums for sometimes information that you didn't want,or information that was incorrect to you.
Look here:~
https://www.scotlandspeople.gov.uk/