I haven't seen the third season yet but it does appear the series hasn't officially ended yet. From Deadline:

The question on the mind of all Ted Lasso fans, and some of its stars, is will there be a Season 4 or any spin-offs of the Apple TV+ series.

Brendan Hunt, who plays Coach Beard in the Warner Bros. Television-produced series, is the latest to respond.

“My pat answer, that is also 100% true: We don’t know. We need a break and will take one presently. Nothing has been ruled out, everything is possible; but that includes the possibility that we’re done. We won’t know until we’ve sat with it for a while [and] decompressed,” he wrote on a Reddit AMA session.

(original source on Reddit)

I've changed the status back to "Returning Series" and locked it. If there is an official announcement that Season 3 was the end or if there no new season or news of a new season during the next year or two (that's my personal baseline for "abnormally long hiatus" but other mods obviously have their own) the status can be changed to "Ended."

In June 2022, Brett Goldstein also commented that the series would end after three seasons—"We are writing it like that." In March 2023, Sudeikis said that the third season "is the end of this story that we wanted to tell", and that there are possibilities for spin-offs. In an interview published in August 2023, Declan Lowney, who directed multiple episodes of the series, reiterated that the third season was "the end for now" and that it would be "two or three years [from filming the season] before anything happens — if anything happens.