Revelation 2:28 New English Translation

²⁸just as I have received the right to rule^[a] from my Father—and I will give him the morning star.^[b]

Revelation 2:28 tn What has been received is not specified in the Greek text, but must be supplied from the context. In the light of the two immediately preceding verses about rulership or dominion, it seems that the implied direct object of εἴληφα (eilēpha) is “the right to rule” (i.e., ἔχειν ἐξουσίαν ποιμάνειν, echein exousian poimanein), although many modern translations supply the word “authority” here (so NAB, NRSV, NLT).
Revelation 2:28 tn On this expression BDAG 892 s.v. πρωϊνός states, “early, belonging to the morning ὁ ἀστὴρ ὁ πρ. the morning star, Venus Rv 2:28; 22:16.”

New English Translation (NET)