X-axis tick format not applying

I'm trying to set a date format for the x-axis of my chart. I referred to https://github.com/d3/d3-time-format#locale_format for the possible values, but no matter what I put in, the format doesn't change.

I found out the problem was the format of the date string. It was formatted as MM/DD/YYYY and plotly needed it to be in YYYY-MM-DD format to recognize it as a date.