Plotly in Retool: custom ticks

I'm trying to build a simple bar chart but can't even get the ticks to work correctly when using tickmode: "array". I've set tickvals and ticktext correctly, this works in python and js with plotly, but not in retool.

Can someone confirm whether this is a bug, missing feature, or if I'm just making an error somewhere?

I imagine it must be a typo somewhere, I have it working with custom xaxis ticks

syntax is like this in my layout :

...
    "type": "linear",
    "tickformat": "",
    "tickmode": "array",
    "tickvals":[0, 1.25, 2.5, 3.5, 4.5],
    "ticktext":["A","B","C","D","E"],
    "automargin": true,
    "fixedrange": true,
...