You were not supposed to touch the lib folder, you'd be looking at creating a custom extension (check Wappler docs on the forum, there's a section for that) or using RunJS to call the Plaid client functions (you installed with npm) 
Any changes you made inside lib folder may be lost upon a Wappler update.
You're using a relative URL, the Wappler editor doesn't know how to interpret that, you need to input the full (absolute) URL.