To create client you need to fill out Client Name [1], Nam space [2], Select Odoo Plan (Odoo version) [3]

SaaS config client info

SaaS config client info

After choosing the Odoo plan [3] then need to select auto-generate subdomain or add your custom domain [4] and chose ssl or not SSL [5] if select True system will auto-generate SSL  (Noted: if you select the custom domain you must point your custom domain to your server before generating an SSL key, finally select [6] to limit Ram & memory or not. and click lunch

Odoo SaaS 2.0 Next screen to create client

Odoo SaaS 2.0 Next screen to create client