const myItem = items.getItem('myItem')
const newTags = [a,b,c,d].toString() // an array as a string. Comes from somewhere else, but not relevant here. It's definitely a string.
myItem.addTags(newTags)
but only one long tag with all commas included is applied to the item.
This does not accept an array object, it needs a string, so I don’t know why this isn’t working.