What does Leviticus 16:13 mean?

He has to put incense on the fire in front of the Lord, so the cloud of smoke covers the lid on top of the covenant chest. That way, he won’t die when he goes in. Leviticus 16:13 - Modern Text Bible

(The priest must use incense to create a barrier of smoke, protecting himself from God’s direct presence, which is dangerous even for him.)