There is documentation page describing how to add gauge widget to 6.4

https://www.zabbix.com/documentation/current/en/devel/modules/tutorials/widget

It was working for version 6.4.3 but 6.4.4 introduced breaking changes and this tutorial wasn't updated. The changes that need to be applied are really small but it must be mentioned that minimum required version is now 6.4.4 . So, 2 things to change on that page:

1. Add 1 code change (remove ms from associated arrays);
2. Add warning about minimum required version (6.4.4) at the beginning of the Part II - Gauge chart section.