For a re-authorization (not applicable for the first authorization), in addition to clicking on "re-authorize" within Flows, the following steps must also be performed:

Step 1
Log into Exact in the administration.

Step 2
Click on your login name (located in the upper right-hand corner of the screen).

Step 3
Select "My Exact Online" > "Go to Security Center."

Step 4
Scroll down to the section titled "Permissions for my apps" > click on Flows.

Step 5
Click on "Manage Administrations" in the bottom right-hand corner.

Step 6
Select the relevant administration you want to add by checking the box in the "Available Administrations" column.

Step 7
Click on the arrow to move the administration to the "Selected Administrations" column.

Step 8
Click on "Save and Close."
It is recommended to check for any blocked permissions in this section.