per https://www.grammarly.com/blog/assure-ensure-insure/:
To ensure something is to make sure it happens—to guarantee it.
To insure something or someone is to cover it with an insurance policy.
To ensure something is to make sure it happens—to guarantee it.
To insure something or someone is to cover it with an insurance policy.
ensure - to make sure, certain, or safe
insure - to make certain especially by taking necessary measures and precautions
https://www.merriam-webster.com/words-at-play/how-to-use-ins...