Accounts per webshop
Give each webshop its own Dropday account. Then add your original login to the new account through Team, so you can switch between your webshops in the dashboard.
Dropday is designed for one webshop per account. You add an account for another webshop by signing up again; you can't add one from inside the dashboard.
Create an account for your other webshop
Log out of Dropday.
On the Dropday website, click Start free trial.
On Create your account, fill in your name, a password and, in Work email, an email address that isn't used for Dropday yet. An address that already belongs to a user is refused.
Submit the form.
This creates a separate login and a separate account, with its own trial. Your other webshop's trial or subscription stays as it is.
Use one login for both accounts
Your original login doesn't get the new account automatically. To add it:
In the new account, open Team in the sidebar under Workspace.
Invite the email address of your original login: fill in Email address, choose a Role (Admin or Order Manager) and click Send invitation.
Log out, open the invitation email and click Accept invitation. Log in with the email address of your original login and accept.
Roles and permissions explains what each role can do.
Switch between your webshops
Once your login belongs to more than one account, the account switcher appears at the top of the sidebar. It shows the domain of the current webshop with an exchange icon. Click it to see your other webshops by name, and choose one to switch the dashboard to that account.
Why not one account for several webshops
With Shopify you can't: an account can have only one Shopify store, and a Shopify store can be connected to only one account at a time.
With the other plugins, Dropday doesn't stop you from using one account's API key and account ID in several webshops. But Dropday checks order numbers across the whole account: if two webshops have an order with the same number, Dropday refuses the second one and it isn't sent to the supplier.
Next, in the new account, connect its webshop.