You need to follow these steps for each shop you wish to connect:
Create New Shopware 5 Connection
Go to the Adribute app.
Navigate to "Connections".
Click on "Create Connection" in the top right corner.
Search for the Shopware 5 connection and select it.
Fill in your Shopware URL, which simply is your Store URL, e.g. https://adtribute.shop.com/
If your store is not hosted by your customer-facing URL, please use the URL which your domain is hosted on. You can find your domains here: "Configuration" > "Basic settings" > "Shop settings" > "Shops", then use the according domain.
Now you need your User ID and API Key from Shopware.
Retrieve User ID and API Key from Shopware
You have to create an API user with the right permissions. First, you have to create a Role with the needed permissions.
Create Role and grant Permissions:
Open Shopware.
Navigate to "Settings" > "User administration" > "Roles".
Cick on "Add role".
Name it "adtribute" and create it.
Now, go to the "Ressources & permissions" tab.
Select the "adtribute" role in the dropdown and select the following permissions:
article (read)
order (read)
Save the role with those permissions and proceed.
Create API user:
Now, within the "User administration" Tab go to "User Management".
Click on "Add user".
Name the user "adtribute"
Enable API access (click checkmark).
Select the "adtribute" role.
The rest of the settings like password and email, you can simply fill out as you wish and save for yourself.
Copy the generated API Key (save it on your device) and save the user.
Paste the API Key in the according field in adtribute.
For the User ID fill in the name for the User you have created in Shopware.
Complete Connection
After you have filled out the URL and User ID and pasted the API Key (and saved the User in Shopware) just click on "Next". It will load for a short bit and tell you on the bottom right if the Connection was successful and show up within your Connections.
You have to repeat those steps for every Shopware store, you wish to connect.