abcjs currently doesn't wrap long text lines in descriptive tags or text annotations:
%%text, %%center, or %%begintext / %%endtext blocks.
I've added a new feature on the "hamburger" menu in the tool that allows you to split any long text in the ABC at a specific length in your tags, text, or both so that they display properly.
You may select which tags you want to split.
You may choose to split either the current tune being worked on or all tunes in the ABC editor.
The splitter attempts to split the text at a word boundary.
Try my free ABC Transcription Tools
https://michaeleskin.com/abc
User Guide
https://michaeleskin.com/userguide