It’s very easy to prove that adoni, a non-deity title
The assertion above is false.
In Judges 6:13 Gideon refers to the Messenger of YHWH as adoni.
Since the Messenger of YHWH is YHWH demonstrates Gideon was referring to YHWH as adoni.
Judges 6:11-23
11 The Messenger of the Lord came and sat under the oak tree in Ophrah that belonged to Joash from Abiezer’s family. Joash’s son Gideon was beating out wheat in a winepress to hide it from the Midianites.
12 The Messenger of the Lord appeared to Gideon and said, “The Lord is with you, brave man.”
13 Gideon responded, “Excuse me,
sir! But if the Lord is with us, why has all this happened to us? Where are all the miracles our ancestors have told us about? Didn’t they say, ‘The Lord brought us out of Egypt?’ But now the Lord has abandoned us and has handed us over to Midian.”
14 The Lord turned to him and said, “You will rescue Israel from Midian with the strength you have. I am sending you.”
15 Gideon said to him, “Excuse me, sir! How can I rescue Israel? Look at my whole family. It’s the weakest one in Manasseh. And me? I’m the least important member of my family.”
16 The Lord replied, “I will be with you. You will defeat Midian as if it were only one man.”
17 Gideon said to him, “If you find me acceptable, give me a sign that it is really you speaking to me.
18 Don’t leave until I come back. I want to bring my gift and set it in front of you.”
“I will stay until you come back,” he said.
19 Then Gideon went into his house and prepared a young goat and unleavened bread made with 18 quarts of flour. He put the meat in a basket and the broth in a pot. Then he went out and presented them to the Messenger of the Lord under the oak tree.
20 The Messenger of the Lord told him, “Take the meat and the unleavened bread, put them on this rock, and pour the broth over them.” Gideon did so.
21 Then the Messenger of the Lord touched the meat and the bread with the tip of the staff that was in his hand. Fire flared up from the rock and burned the meat and the bread. Then the Messenger of the Lord disappeared.
22 That’s when Gideon realized that this had been the Messenger of the Lord. So he said, “Lord God! I have seen the Messenger of the Lord face to face.”
23 The Lord said to him, “Calm down! Don’t be afraid. You will not die.” (GW)
Verse 12 - The Messenger of YHWH appears unto Gideon.
Verse 14 - The Messenger is described as the Lord (YHWH) which spoke unto Gideon.
Verse 17, 18 - Gideon asks "Him" (the Messenger of YHWH) not to depart.
Verse 18 - The Messenger of YHWH says He will wait until Gideon returns.
Verse 19 - Gideon brings out the food unto the Messenger of YHWH under the oak tree. This is where the Messenger of YHWH was originally (verse 11).
Verses 20-22 - Describes what the Messenger of YHWH did to Gideons' offer.
Notice also in verse 22 that Gideon realized that the Messenger to whom he referred to as "sir" (adoni) in Judges 6:13 was in fact YHWH! By seeing the Messenger (YHWH) face to face Gideon was in fear that he would die (cf. Exodus 33:20). This is why in the very next verse (23) YHWH assures Gideon that he will not die even though Gideon saw YHWH face to face.