You can force a update check in ≡ -> Help -> About Firefox.

For more information on the update process, see Update Firefox to the latest release.

Hi Alice I do not see a update button in the about page or in the settings, I am seeing the version only. I am beginning to think there is a policy rule being applied to my computer that is making the browser remove the update button or grey out the update in settings. My other browsers are updating but those are chrome browsers. Would downloading a Firefox 148.msi application update the browser and keep all my settings?

Here is a screen shot of the "about" page.