The first Noahide Law is “Do not profane G‑d’s Oneness in any way. Acknowledge that there is a single G‑d who cares about what we are doing and desires that we take care of His world.”
The trinity is a form of soft polytheism that includes that their one god consists of three gods “father, son and Holy Spirit.” Most Christian denominations believe in the trinity.
Hinduism worships a Brahman god who consists of 33 million gods
How is the trinity that much different from Brahman? So if a Trinitarian Christian tells you that their god is the same G-d as yours, how would you respond? Does mitzvot tell you not to misguide people about the oneness of your G-d?