ENS App and Explorer are on the Sepolia testnet. Features may change before mainnet.
Before ENSv2, a name could have an Owner and a separate Manager. The Manager could edit the name's records and create subnames, while the Owner kept the name itself.
ENSv2 has no Manager. Instead, you give a second (and additional) wallets only the roles it needs, in ENS Explorer.
Where the Manager's jobs went
Edit records: roles on the name's resolver, such as Set Address and Set Text.
Create subnames: Registrar on the name's own registry.
Point the name at another resolver: Set Resolver on the name. Steps: Grant registry 'roles' to manage your name
Each role also has an Admin level, which lets a wallet give the role to others. Keep Admin with your own wallet.
Let another wallet edit your records
Open your name's Roles tab. Under the resolver table, select View and manage, then Add user, and tick the records it can set. This covers every name on the resolver. Guide: Grant resolver 'roles' to edit name records
Let another wallet create subnames
Open your name's Roles tab. Under your name's own registry table, select View and manage, then Add user, and tick Registrar. No registry yet? Set one up first: Create a subname (ENS Explorer).
If your name had a separate Manager
When you upgrade, a box offers to keep that wallet as a manager. It starts unticked. Ticked, it gives the wallet Set Resolver at User level. Either way, the wallet gets no record roles: give them after the upgrade, as above. Until then, the name won't show under My Names in the ENS App for that wallet.
How it all fits together: Registry and resolver: what's the difference?. All roles explained: Grant registry 'roles' to manage your name.