Habemus altare in Greek

Here is from Ellopos Greek NT, Hebrews 13:10 as you see here:

10 ἔχομεν θυσιαστήριον ἐξ οὗ φαγεῖν οὐκ ἔχουσιν ἐξουσίαν οἱ τῇ σκηνῇ λατρεύοντες·
10 We have an altar, whereof they have no right to eat which serve the tabernacle.

Please note, θυσιαστήριον, not βημα. Same word as in Genesis 8:20, as you see here:

20 καὶ ᾠκοδόμησε Νῶε θυσιαστήριον τῷ Κυρίῳ, καὶ ἔλαβεν ἀπὸ πάντων τῶν κτηνῶν τῶν καθαρῶν καὶ ἀπὸ πάντων τῶν πετεινῶν τῶν καθαρῶν καὶ ἀνήνεγκεν εἰς ὁλοκάρπωσιν ἐπὶ τὸ θυσιαστήριον.
20 And Noe built an altar to the Lord, and took of all clean beasts, and of all clean birds, and offered a whole burnt-offering upon the altar.

The basic meaning of θυσιαστήριον is tool for sacrifice. Sacrifice tool or sacrifice place./HGL