Business Search - set up UI in sandbox environment

After a brief investigation Kial has the following comments about this task:

`there are some things we need to update in the backend auth config for the sandbox to get the UI connection working. It will cause a brief outage for the sandbox and it will be a bit longer (thor and I chatted and we think it will be about a half day)`

Review the sandbox backend authentication configuration and the UI connection path described in the issue. Confirm the required changes with the team before making them, since the work is expected to cause a brief sandbox outage. Done means the UI connects successfully in the sandbox and the outage is communicated.

Written by the indexing model from the issue text.