The upgrade is only supported from 6.x to 6.x and 7.x to 7.x, with an expected small downtime window.
In the Rancher UI, go to the project i.e., global | your cluster | project name (usually the default).
Do not select the 'Upgrade available' button in 'Apps'. You will lose all your data!
Select your app to see the workloads.
Each primary node, secondary node(s) and nginx is updated. Each workload is upgraded by changing the Docker image
Select the three vertical dots to the right of the primary node and select View | Edit YAML.
Rancher displays a text editor.
Search and replace all occurrences of the old Artifactory tag (e.g., 7.3.2) with the version you want to upgrade to (e.g., 7.6.3).
Wait for the primary node to turn green in the Rancher UI. You can also watch the status of various nodes in Artifactory UI under Settings | Monitoring | Service Status.
Repeat steps 4-6 for the secondary nodes.
Repeat steps 4-6 for nginx.
Log into Artifactory and verify that all the nodes are now in the correct version of the UI | Administration | Monitoring | Service Status.