Enable the Allow run promotion feature within the Spacelift Stack's Settings.
Promote from Proposed Run View
Assuming you've enabled Run Promotion within the stack settings, and the commit to be promoted is newer than the stack's current commit. On a given proposed run, you will then see the "Promote" button as seen in the screenshot below. You simply need to click this button to promote the proposed run into a tracked run.
Promote a proposed run within Spacelift using the Promote button.
Promote from a Pull Request
For Spacelift users utilizing GitHub, a similar feature is available directly from the GitHub Pull Request. Assuming the same criteria is met as mentioned previously: 1) The commit to be promoted is newer than the stack's current commit 2) Run Promotion is enabled on the stack - Then, you will see a Deploy button available within the Checks tab of the pull request. This button will promote your proposed run into a tracked run.
Promote a run from a GitHub Pull Request using the Deploy button.