How to index into an array of integers in a placeholder expression

I feel like such a noob asking this question… but…

I’m building an automator.

I’ve done an API GET agent details

I’ve parsed that in a parser node: P5.

I’m seeking to pull out the agent groups that the agent is a member of, specifically just the first one.  I can do this by configuring the json parser to return a scalar integer for member_of instead of returning an array of integers - but this feels brittle to me.  The moment that someone regenerates that parser node, it will break.

I want to access the first element of the array of integers in a placeholder expression, but for the life of me, I can’t figure out the right syntax, and half an hour of googling has brought me no closer to a resolution.

This place holder:

{{P5.root.agent.member_of.member_of_number}}

...returns an array of integers which is the agent groups for the agent I'm GETting.  I’ve tried the following placeholder variations, and they all return nulls:

{{P5.root.agent.member_of[0]}}

{{P5.root.agent.member_of.member_of_number[0]}}

For the love of god, what am I doing wrong??  How do I index into this array?

(PS, for those of you laughing at my API/Freshservice noobness, I’m a killer TSQL developer… so a bit out of my comfort zone!)