A cloud flow that has no successful triggers will expire and be turned off. After 90 days of inactivity, the flow creator will receive an email. If no action is taken in next 30 days, the flow will be systematically turned off and the creator will be notified in an email. For enterprise scenarios, we recommend you buy a standalone Power Automate license listed in Pricing article to ensure your flow isn’t turned off due to inactivity. You can turn your cloud flows back on anytime.
Read more on expiration limits
Workaround #1: Cause the flow to run manually
The fastest, short-term solution is to make sure your flow is triggered by performing some manual action. The action depends on the type of triggered used by your flow. If you are not sure - navigate to the flow and switch to the edit mode. Then verify what triggered is used.
Workaround #2: Using Premium License
Flows disabled after 90 days of inactivity is by design for users with Community and Microsoft 365 Plans. We can upgrade to a "premium" license for Power Automate in order to bypass the expiration limitation:

Workaround #3: Create a new flow
We can't control this behavior directly. There is no setting we can tweak to prevent flows from being disabled after 120 days of inactivity.
That being said, we can create a new flow that will create a "TEST" list item every 90 days and then immediately delete it. This will indirectly cause the original flow to trigger, which, in turn will reset the 90 day timeout period.
Create a new Flow
- Create a new flow with a Recurrence (Scheduled) trigger. Configure it to run every 90 days.

- In this flow, create two actions:
- Create item. Give it a "TEST" title.
2. Delete item. Pass ID of the item that we created a step earlier. Essentially, all we do is create an item and then immediately delete it.

- Now save the new flow. Don't forget to give it a good name.
Update the original flow
- Open the original flow and switch to Edit mode.
- Right after the trigger, add a Condition.
- In the condition, check if the Title equals to TEST.
- Inside if yes - add a Terminate step.
- Set Status to Canceled.

- Save and close this flow.
Workaround #4: Automatically turn on disabled flows
Credits to Mohsen Sichani and Pieter Veenstra. Original solution: Automatically re-enable flows that were suspended in Power Automate
- Create a new flow that will run every day.
- Add an action to search for suspended Flows:

