Ok, step back. What are you trying to do? If you are the admin, you're already in the group.
Sorry, mistake in question.
I have transferred spaces from the server and there is no access to editing some pages, the system administrator is for this purpose necessary, and he is absent.
Ok, but you have admin already, so you can just change the permissions on the space.
Pages are in "forbidden". And I see warning: "There aren't enough powers"
Same answer - you get an existing system administrator to add you to the system-administration group(s)
If you don't "have enough powers", then you are not an administrator, and need to ask one to make you so.
So, the group exists, and from this behaviour, it is a group named for system-admin access.
As I already said before, you will need an existing system admin to add you to it.
However, now you've posted the text, I can see that you are on Cloud. Where only Atlassian get system admin access. So you will not get that.
As to me to get pages from forbidden?
I think that only the system administrator can do it
No, any admin can go to the space settings.
i'm in space permissions
Trouble in "Запрещенные страницы" - Это "Forbidden pages"
Also, one thing of note if you are on Confluence Cloud you cannot become as system administrator. That role is reserved for Atlassian. The most you can be is a Confluence Administrator.
I have created the new administrator and everything has earned! thanks!