This article argues effectively that Christ presented Himself in heaven for the forgiveness of humanity’s sins. The only quibble I have is that no ancient Jewish or early Christian source labels the high priest’s inner-sanctum blood manipulation an “offering.” 

https://www.desiringgod.org/articles/our-welcome-to-heaven

Lev. 6.30 explains: But any sin offering whose blood is brought into the tent of meeting to make atonement in the Holy Place must not be eaten; it must be burned up. Here is mention of the sin offering’s blood to be brought into the Holy Place for atonement of sins.

Lev. 10.18 also notes aspects of the different sacrifices and instructs that the animal’s blood that is presented in the Holy Place makes atonement: “Since its blood was not taken into the Holy Place, you should have eaten the goat in the sanctuary area, as I commanded.”

Finally, Lev. 16.11-17 gives the mechanics where first Aaron (or his sons) makes propitiation for their own sins and then the animal’s blood for the congregation’s sins are brought into the inner sanctuary for sprinkling upon the atonement cover of the ark:

“Aaron shall bring the bull for his own sin offering to make atonement for himself and his household, and he is to slaughter the bull for his own sin offering. He is to take a censer full of burning coals from the altar before the Lord and two handfuls of finely ground fragrant incense and take them behind the curtain. He is to put the incense on the fire before the Lord, and the smoke of the incense will conceal the atonement cover above the tablets of the covenant law, so that he will not die. He is to take some of the bull’s blood and with his finger sprinkle it on the front of the atonement cover; then he shall sprinkle some of it with his finger seven times before the atonement cover.

“He shall then slaughter the goat for the sin offering for the people and take its blood behind the curtain and do with it as he did with the bull’s blood: He shall sprinkle it on the atonement cover and in front of it. In this way he will make atonement for the Most Holy Place because of the uncleanness and rebellion of the Israelites, whatever their sins have been. He is to do the same for the tent of meeting, which is among them in the midst of their uncleanness. No one is to be in the tent of meeting from the time Aaron goes in to make atonement in the Most Holy Place until he comes out, having made atonement for himself, his household and the whole community of Israel.

All the bolded quotes are from the NIV. Perhaps the Hebrew does not mention an “offering” but I am at a loss for what else they could be if they were not some kind of presentation or offering. This is nevertheless a good article which explains the scene as described in the book of Hebrews.