Trying to make it active requires moving the key information to the end of the sentence:

"The time you spent in training last year entitles you to jump pay [for that time]."

Although style guides like this one usually advise against using passive voice because it makes things harder to read, clarity should be the goal, not just active voice. This is a good example of a reason you might prefer passive voice: because the verb's subject isn't the focus. Passive voice can also be clearer than active voice when there's no relevant or meaningful actor to use as the subject.