To connect Fieldmagic to Reckon Accounts Hosted, you will first need to set-up a dedicated account to connect Fieldmagic to, which has Administrator rights.
Step 1: Set-Up Users and Roles
A prompt for the password is required:

Enter Password Details:

Create a new user which will be used for connecting to Fieldmagic:

Step 3: Make sure all the "Available Roles" are added to the "Assigned Roles"
Ensure all access permissions are added to this user:

Select OK and then close the Users and Roles window.
Step 4: Switch it to Multi-User mode:
You will need to then switch to multi-user mode so multiple users can be logged in to Reckon at the same time:

Step 5: Complete
Now when you connect Fieldmagic to Reckon, you can use the dedicated login you have created to connect.