“Advice For Failing To Obey Sign Ticket (hta 182(2)). Took A Left Turn Where It Was Prohibited”

Hi everyone, hoping to get advice on how to proceed with dealing with a HTA 182 (2) Failing to Obey Sign ticket that I got in Orangeville at the intersection of 3rd Street and Broadway. I made a complete stop at the stop sign but took a left turn onto Broadway where apparently making a left turn was prohibited. I could not see the left turn prohibited sign and Google Maps suggested making a left turn. Since I couldn't see any sign telling me that a left turn was prohibited, I followed Google Maps and made the left turn and was instantly pulled over (cop was probably sitting there watching the intersection).

My question is - how should I proceed with dealing with this ticket? Based on my research the Early Resolution option sounds like the most suitable option. The cop told me I could talk to a prosecutor and they might reduce it to a by-law charge. Is my understanding of this situation correct or would you recommend I just pay the fine or request a trial (wouldn't want a trial since I don't want to waste my time and money on legal fees, etc.). Any advice would be great! Thanks

Edit: Additional info:

I looked up the intersection on Google street view, and there seems to be a Left Turn Prohibited sign behind the stop sign. I'm from Toronto and here we have these signs in front instead of on the side (which makes it hard to see). This was an honest mistake and I don't want it affecting me too much.