"These links will be shown in the 'Actions' context menu for the transaction detail." => "These links will be shown in the 'Actions' context menu for transactions."

"i.e." => "e.g."

TBC
Pinging @elastic/apm-ui (Team:apm)
While fixing these, I wonder if it's not too late to change the title of this page as well.

According to the product naming guide (internal link), Kibana apps, like the APM app, are not supposed to be called UIs. Would _Customize app_ be better? Or even just _Customize_?
I don't think the single quotes are needed around actions. I think this is fine:
The links will be shown in the Actions context menu for transactions.
If we're going to stick with "e.g.", don't forget the commas before and after it. Something like:
No custom links found. Set up your own custom links, e.g., a link to a specific dashboard,
or an external link to a company website.
Would Customize app be better? Or even just Customize?
Changed it to Customize app.