Click 'Create TLD Account' if you want to issue domain names, and click 'Create Domain Account' if you want to own a domain.
Enter an existing seed here (accepts both BNS Seed Format and regular seeds):
Quick Guide
Open this site in a second tab
In this tab (Domain tab), click "Create Domain Account". Note down the seed and address
In the second tab (TLD tab), click "Create TLD Account". Note down the seed and address.
Send a Banano to your TLD Account's address
On TLD tab, click "Receive"
On TLD tab, fill in the "Name (no '.', '"', max 32 chars [32 bytes]):" field with "helloworld", fill in the Domain tab's address in the "Send to address:" field and click "Issue domain"
Wait until it sends, and open the block explorer link in a new tab, noting the block hash
Back to the Domain tab, fill in that block hash into the "Block hash of Domain Transfer:" input
Then, in the right hand "Domain Resolver" panel add the TLD tab's address to the "TLD Mapping". Call it "demo"
In "TLD name (no dot):", write "demo" and then click "Detect held domain name"
It should now say "Name: helloworld" right below "Domain Account Manager". Congratulations! You own a Banano domain name now
Fill in your actual main Banano address in "Resolve to address:", and click "Declare address to resolve to", and anyone using your TLD can now turn "helloworld.demo" (or whatever they name your TLD) into your address
Add this address to the mapping (right panel) with whatever name you want. Before issuing, make sure to CHECK what domain names you have already issued (right panel). If you try to issue a domain name you have already issued, it will not work!!! Or, it should not. Please report if it does; that is a bug.
Oh, also, obviously make sure you've sent some Banano to the address (and clicked the receive button below).