# Having an issue connecting to pdfjs.express from one of our servers, getting Failed to fetch errors. Our firewall team needs to open access, Which IP address do we need to allow connectivity to?

**URL:** <https://pdfjs.community/t/having-an-issue-connecting-to-pdfjs-express-from-one-of-our-servers-getting-failed-to-fetch-errors-our-firewall-team-needs-to-open-access-which-ip-address-do-we-need-to-allow-connectivity-to/3136>\
**Category:** Technical Support\
**Created:** [February 16, 2024, 9:54am UTC](https://pdfjs.community/t/having-an-issue-connecting-to-pdfjs-express-from-one-of-our-servers-getting-failed-to-fetch-errors-our-firewall-team-needs-to-open-access-which-ip-address-do-we-need-to-allow-connectivity-to/3136 "2024-02-16T09:54:45Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![lunga.vazi](https://avatars.discourse-cdn.com/v4/letter/l/46a35a/32.png) [@lunga.vazi](https://pdfjs.community/u/lunga.vazi)\
**Post date:** [February 16, 2024, 9:54am UTC](https://pdfjs.community/t/having-an-issue-connecting-to-pdfjs-express-from-one-of-our-servers-getting-failed-to-fetch-errors-our-firewall-team-needs-to-open-access-which-ip-address-do-we-need-to-allow-connectivity-to/3136/1 "2024-02-16T09:54:45Z")

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**Which product are you using?**

**PDF.js Express Version**

**Detailed description of issue**  
Having an issue connecting to [pdfjs.express](http://pdfjs.express) from one of our servers, getting Failed to fetch errors. Our firewall team needs to open access, Which IP address do we need to allow connectivity to?

**Expected behaviour**  
Viewer to show the pdf file.

**Does your issue happen with every document, or just one?**  
All documents.

**Link to document**  
{Provide a link to the document in question if possible}

**Code snippet**  
We are using the viewer library to authenticate lisense key.

---

<div class="post-metadata">

**Author:** ![tgordon](https://avatars.discourse-cdn.com/v4/letter/t/aca169/32.png) [@tgordon](https://pdfjs.community/u/tgordon)\
**Post date:** [February 20, 2024, 8:06pm UTC](https://pdfjs.community/t/having-an-issue-connecting-to-pdfjs-express-from-one-of-our-servers-getting-failed-to-fetch-errors-our-firewall-team-needs-to-open-access-which-ip-address-do-we-need-to-allow-connectivity-to/3136/3 "2024-02-20T20:06:42Z")

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Hello lunga.vazi,

What fetch request are you doing?  
If you are using the REST API it should be:

```javascript
https://api.pdfjs.express

```

Best regards,  
Tyler