Did the male cult prostitutes in the OT serve male or female clients?

Judah's daughter-in-law pretended to be a prostitute in Genesis 38:

15 When Judah saw her, he thought she was a prostitute, for she had covered her face.

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she was a prostitute
לְזוֹנָ֑ה (lə·zō·w·nāh)
Preposition-l | Noun - feminine singular
Strong's 2181: To commit adultery, to commit idolatry
Strong's Hebrew: 2181. זָנָה (zanah) — 93 Occurrences

H2181 was the common Hebrew word for a harlot. Judah hired a prostitute to satisfy his sexual urges.

Afterward, Judah sent his friend to look for her:

21 And he asked the men of the place, “Where is the cult prostitute who was at Enaim at the roadside?” And they said, “No cult prostitute has been here.”

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cult prostitute
הַקְּדֵשָׁ֛ה (haq·qə·ḏê·šāh)
Article | Adjective - feminine singular
Strong's 6948: A female devotee
Strong's Hebrew: 6948. קְדֵשָׁה (qedeshah) — 5 Occurrences

Now the Hebrew word was different. H6948 was a technical term for a female cult devotee in charge of fertility rites, where sexual acts were performed as a means of promoting fertility and ensuring agricultural abundance.

Elsewhere in 1 Kings 14:

24 and there were also male cult prostitutes in the land. They did according to all the abominations of the nations that the LORD drove out before the people of Israel.

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male cult prostitutes
קָדֵ֖שׁ (qā·ḏêš)
Adjective - masculine singular
Strong's 6945: A, sacred person, a, devotee, to licentious idolatry
Strong's Hebrew: 6945. קָדֵשׁ (qadesh) — 6 Occurrences

There were female [H6948] and male [H6945] cult prostitutes/priests/priestesses.

Deuteronomy 23:

17 No Israelite man or woman is to become a shrine prostitute [H6945].

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The belief was that engaging in sexual activity with a temple prostitute would invoke the favor of the gods and bring about blessings in various areas of life.

Did the H6934-male cult prostitutes in the OT serve male or female clients?

The issue was more complicated. On one side, they were not exactly commercial prostitutes in the H2181 sense. On the other side, their 'clients' were not exactly clients in our modern commercial sense either. Perhaps, in some instances, some males paid some male cult prostitutes to satisfy their homosexual urges but that might not be the usual practice.