As per the description above, you want to access the services of Adobe PDFPack through a browser, Is that correct?
You can also use the free desktop version of Adobe Reader DC to use the services of Adobe PDFPack, justs "sign-in" with your current Adobe ID and password in Adobe Reader DC. To download Adobe Reader DC, use the URL Adobe - Adobe Acrobat Reader DC Distribution
For troubleshooting, you may refer to Troubleshooting Create PDF, Export PDF, Adobe Send, Fill & Sign … services(PDFPack or Document Cloud...
Feel free to update this discussion in case you need further assistance.