I'm afraid you can't. Even if you buy NFT Collection Maker 2.0 Agency without the Standard Version, you will not be able to login.
Here is why:
1. NFT Collection Maker 2.0 Standard is the main product which is either a Monthly, Yearly or One Time Subscription.
2. NFT Collection Maker Agency 2.0 is an Upgrade or Up-sell which adds the Agency features in your NFT Collection Maker 2.0 account.
3. Since NFT Collection Maker 2.0 Agency is not independent, you will need to subscribe for the main product NFT Collection Maker 2.0 Monthly, Yearly or One Time subscription first. Else you can't login with only NFT Collection Maker 2.0 Agency in your account.