Due to updated to Twitter’s API you can no longer use the twitter widget to embed your timeline. This is due to changed made by Twitter (now X)
You can still embed individual tweets by pasting in the url to a tweet.
You can embed a twitter profile with tweets using the Jetpack Twitter widget. But you can also embed a tweet or timeline by pasting the link to the tweet into a post or page.
You need to have the Jetpack plugin activated and turn on it’s shortcode module. You only need to paste a link to a tweet.
You can even control the amount of space that the tweet(s) take up by using a shortcode:
[twitter-timeline username=glowscot height=300 width=600 ]
gives:
Tweets by @glowscot