Food for thought: The success of any training will be measured by the metrics you report on. So if you're focusing on completion rates, leadership and your board will always ask you to increase that rate as the goal for future trainings. However, completion doesn't equate to actual compliance.
If you can, pivot from reporting out on completion statistics and instead tie your training to rates of compliance. For example, "within six months of releasing COI training, we received an increase of % more proactive inquiries and disclosures than in the same period last year."
This way, you can spend your precious time trying to increase positive compliance outcomes instead of chasing after completion rates (which, let's face it, is exhausting).
That being said, you do want folks to complete their training, so if they're not, it's a good opportunity to pick up the phone and find out why they're ignoring it. You may find that they think it's irrelevant, takes too much time, notifications were stuck in spam, won't load on their device, or some other root cause that you can quickly fix. (Bonus! having these convos can turn a naysayer into a champion).And for those who think they're above the rules and too important to do training, org them out! Work with HR to ensure that training completion is tied to performance evaluations, promotion, and raises. In other words, if you don't complete your training, you can't move up. Otherwise, you'll put people who don't care about compliance in leadership positions and the problem will never go away. Tone from the top, as they say.