Rails 7 Highcharts ganttChart is not a function - ruby-on-rails

Question

Highcharts is working when not calling Gantt chart in other views. I've played around trying to get this Gantt chart to work. Looks like there is a conflict with import map only calling highcharts and highcharts.ganttChart is not found. I've tried added the src url through a script tag directly in the html view but still getting this error.
Error msg <
Uncaught (in promise) TypeError: Highcharts.ganttChart is not a function
>
Javascript controller
```
import {Controller} from "#hotwired/stimulus"
export default class extends Controller {
connect() {
let today = new Date(),
day = 1000 * 60 * 60 * 24;
today.setUTCHours(0);
today.setUTCMinutes(0);
today.setUTCSeconds(0);
today.setUTCMilliseconds(0);
today = today.getTime();
let dateFormat = Highcharts.dateFormat;
let series
let chart; // global
async function requestData() {
const response = await fetch('http://localhost:3000/api/v1/charts/index');
if (response.ok) {
const data = await response.json();
series = data.map(function (job, i) {
let data = job.deals.map(function (phase) {
return {
id: 'deal-' + i,
project: phase.project,
client: phase.client,
phase: phase.phase,
start: new Date(phase.from).getTime(),
end: new Date(phase.to).getTime(),
y: i
};
});
return {
name: job.name,
data: data,
current: job.deals[job.current]
};
});
setTimeout(requestData, 1000);
console.log(series);
chart = Highcharts.ganttChart('container', {
series: series,
title: {
text: 'Crew Schedule'
},
tooltip: {
pointFormat: '<span>Client {point.client}</span><br/>' +
'<span>Project: {point.project}</span><br/>' +
'<span>Phase: {point.phase}</span><br/>' +
'<span>From: {point.start:%e. %b}</span><br/><span>To: {point.end:%e. %b}</span>'
},
lang: {
accessibility: {
axis: {
xAxisDescriptionPlural: 'The chart has a two-part X axis showing time in both week numbers and days.',
yAxisDescriptionSingular: 'The chart has a tabular Y axis showing a data table row for each point.'
}
}
},
scrollbar: {
enabled: true
},
rangeSelector: {
enabled: true,
selected: 0
},
accessibility: {
keyboardNavigation: {
seriesNavigation: {
mode: 'serialize'
}
},
point: {
valueDescriptionFormat: 'Assigned to {point.project} from {point.x:%A, %B %e} to {point.x2:%A, %B %e}.'
},
series: {
descriptionFormatter: function (series) {
return series.name + ', job ' + (series.index + 1) + ' of ' + series.chart.series.length + '.';
}
}
},
xAxis: {
currentDateIndicator: true
},
navigator: {
enabled: true,
liveRedraw: true,
series: {
type: 'gantt',
pointPlacement: 0.5,
pointPadding: 0.25,
accessibility: {
enabled: false
}
},
yAxis: {
min: 0,
max: 3,
reversed: true,
categories: []
}
},
yAxis: {
type: 'category',
grid: {
columns: [{
title: {
text: 'Crew'
},
categories: series.map(function (s) {
return s.name;
})
}]
}
}
})
}
return chart;
}
window.addEventListener('load', (event) => {
requestData();
});
}
}