To set trigger in google apps script through a dialog in the script editor, follow these steps:

1. From the script editor, choose Edit > Current project’s triggers.
2. Click the link that says: No triggers set up. Click here to add one now.
3. Under Run, select the name of the function you want to trigger.
4. Under Events, select either Time-driven or the Google App that the script is bound to (for example, From spreadsheet).
5. Select and configure the type of trigger you want to create (for example, an Hour timer that runs Every hour or an On open trigger).
6. Optionally, click Notifications to configure how and when you are contacted by email if your triggered function fails.
7. Click Save.

set trigger in google apps script

In script editor click on the clock icon.

after that, you will redirect to the trigger page. Click on the Add trigger (Right Bottom on Page)

After that a pop-up window will open, you will select the value from there

When you save it you have to authorize the code