“It’s Your Call” Means the Decision Is Yours

“It’s your call” is natural in everyday Australian English. It means “the decision is yours”, not “this is your phone call”. Here, call is a noun meaning a decision or judgement.

A: Should we book the early train or the late one?
B: I can do either. It’s your call.

The expression often respects the other person’s choice, but it can also hand over responsibility. In an important decision, saying only “It’s your call” may sound as though you do not want to take a position. A more collaborative version is, “I’m happy with either, so it’s your call.” By contrast, “Give me a call” does refer to phoning someone. This decision sense is not uniquely Australian; it is also common in British and American English.

https://dictionary.cambridge.org/dictionary/english/call