This article describes in details on how to create an L1 on Avalanche with Starter or Pro plan on either Testnet or Mainnet with Advanced Setup.
Customers can create an L1 on Avalanche directly with AvaCloud Portal.
After customers click on the Testnet on the screen above, they are given choices of Testnet Starter, Testnet Pro and Testnet Enterprise.
There are similar plans on Mainnet, including Mainnet Starter, Mainnet Pro and Mainnet Enterprise.
This article use the screenshots when creating an L1 on Testnet.
There is a separate article focusing on creating an L1 with the Testnet Starter/Free Trial plan. This article focus on the Testnet Pro and Mainnet Starter and Mainnet Pro.
Subscription payment
After Testnet Starter Pro is selected, customers are navigated to the Stripe screen to pay for the plan.
After payment, customers are redirected back to AvaCloud Portal to create an L1. It presents choices of Basic Setup and Advanced Setup. This article focuses on the Advanced Setup which allows customers to fine tune every configurations. 
L1 set up
First, AvaCloud needs to make sure Avalanche Testnet is connected. (Note: on Mainnet, it would ask customers to switch to Mainnet.)
Then customers can go through a series of screens to set up their own L1.
General information
Interoperability
Customization
Transaction manager
Contract manager
Native token minter
Rewards
Fees
Review of all customization by precompiles
Initial native token supply
Control keys
Customers can specify multi-signers to sign transactions for creating the L1 blockchain.
Region for nodes
Summary for review
After "Create L1" button is clicked, customers are navigated to the steps to create blockchain.
Create blockchain
The user is now able to start signing the transactions to create the network and the blockchain. On Testnet, AvaCloud will first check if the connected wallet has enough AVAX token to pay the transaction fee for creating the network and blockchain. If not, it will prompt a flow for customers to get airdrop, and then transfer to P-Chain.
On Mainnet, customers would need to transfer/buy enough AVAX as specified on the UI into their C-Chain address, then transfer to P-Chain address.
After clicking on the “Sign L1 Transaction”, Core Extension prompts the customer to approve the transaction.
For the Create Blockchain transaction, the user will need to select a signer from the Control Keys setup during the configuration phase.
If there are multiple signers, all signers will be required to sign the transaction by using the proper link.
After all signers have signed the transaction, users can click on “Submit Transaction”.
Add validators
AvaCloud will handle the requests to create nodes and blockchains. During this period, users will see a status for their L1 setup below, letting them know there is no action required for them.
Once it is finished, an email is sent to the customer’s email address, notifying them that they can continue their setup.
Customers can click on "Go to Setup" to continue. First they need to set up each validators for the Primary Network.
(On Mainnet, this step is not needed as the validators has been set up by AvaCloud via staking to the Primary Network.)
Add validators to the L1
Once validators have been set up, the customers can then add these validators to the L1. For a single signer, the customers must use a wallet that is on the control key list or the transaction will fail. For multi-signer, customers would need to share each link to other control key holders, as those holder can sign the transaction.
The customers can go through each validator, and sequentially sign the transactions to add each of them to the L1.
Setup complete
After all validators have been added to the Subnet, information shows up on each tab of the L1, except the dashboard, which shows the following
