PR attachment download in BPM Worklist encountered message "This site can't be reached" in Lower Env

When I tried to download an attachment in the BPM worklist from PR Attachment, I encountered "This site can't be reached" in the Lower Environment.

This site can’t be reached

The webpage at https://enaa-dev2.fa.us6.oraclecloud.com/integration/services/DownloadAttachmentServlet?bpmWorklistContext=b5c24eb0-f2bc-424a-9baa-afe1682640fe%3B%3BG%3B%3BTjSNyuNhODVaaMjykBDXH7yr7sRvvaQjujXuUODvtNaucD1OyX3J%2Fm%2FFtNqKkz1IbpC5JQg3uPng2a3yMF%2BQCPjO8WgS%2Fd4NI4hsYWI0TquuHMc%2FZkenYXspNshICmky8eWqRbw0FlbtfDWdWN9uhMDIl2%2BmkQg47gxM%2Ff4kjdR69BnrEHLSGuREd45HgWclNQJryRw37j0H5F9P54ydvg%3D%3D&bpmWorklistTaskId=61a5858d-50bf-4df9-ac8c-b48d82eb6320&QueryAttachment=QueryAttachment&WFTASK_ATTACHMENT_NAME=Line+2%3A+To+Approver_Line2.txt&bpmWorklistTaskVersion=1&cid=917d9975-c4f8-4c36-a888-789eb1f97c7b