Hi,
I have multiple environment and every environment have different deployUrl, because of that, I got this error.

My configuration as follow:

Is there any way I can add deployUrl pdfDefaultOptions.assetsFolder?
Thanks.
This attribute is new to me. But I suppose you also have to configure the baseHref:
<!DOCTYPE html>
<html lang="en">
<head>
...
<base href="/path/" />
I can only guess (because it's also new to me), but I suppose you can also configure this in the baseHref key of your angular.json, just below the deployUrl.
Does this answer the question? I so, give me a short "ping" so I know I can close the issue.
Thanks in advance,
Stephan
For my case, I can't configure both to same value.. Currently, all my assets will under https://10.1.64.21/fssm/public/assets/. Later, in production, we will store all our assets at ./fssm/public/prod/assets/
I see. Well, you can also override the default options:
pdfDefaultOptions.assetsFolder
Thanks @stephanrauh, it solved.

After overriding,

That's great news! Why I wrote my answer, I was in a hurry, so I didn't find the time to mention the feature is even documented: https://pdfviewer.net/troubleshooting (second paragraph).
BTW, it seems you didn't activate the map files. Debugging ngx-extended-pdf-viewer is more fun when you see the real source code.
Most helpful comment
Thanks @stephanrauh, it solved.
After overriding,