What you need
Three things, and all of them are usually already in place in an organisation running SharePoint Online.
A tenant and an app catalogue
You need SharePoint Online with an app catalogue. Most tenants already have a tenant level catalogue. If yours does not, a SharePoint administrator can create one in the SharePoint admin centre under more features, and it takes a few minutes to appear.
If you would rather try a tool on one site before letting it loose everywhere, create a site collection app catalogue on that site instead. The package is then available only there.
Somebody who can approve permissions
Tools that read tenant data raise a permission request when the package is uploaded. Approving it is one screen in the Microsoft 365 admin centre and needs a global administrator or a SharePoint administrator, depending on how your tenant delegates that role.
Modern pages
Every tool targets modern SharePoint pages. Classic pages are not supported and will not be, because the framework these are built on does not run there.