Hebrews 9:
Is the shedding of blood required for the forgiveness of sins?
Yes, initially, at the inauguration of the covenant. After that, believers could claim the blood as part of the requirements for the forgiveness of sin.
God told Moses in Exodus 33:
See also How were intentional sins forgiven in the OT?.
That's the context. The blood was related to the inauguration of the first covenant.18 Therefore not even the first covenant was inaugurated without blood.
When Jesus inaugurated the new covenant, he shed his blood.22 Indeed, under the law almost everything is purified with blood, and without the shedding of blood there is no forgiveness of sins.
Is the shedding of blood required for the forgiveness of sins?
Yes, initially, at the inauguration of the covenant. After that, believers could claim the blood as part of the requirements for the forgiveness of sin.
God told Moses in Exodus 33:
God can forgive whomever he wants.19b I will be gracious to whom I will be gracious, and will show mercy on whom I will show mercy.
See also How were intentional sins forgiven in the OT?.