### Check for existing issues

- [x] I have searched the existing issues and checked that my issue is not a duplicate.

### What happened?

If you bulk create internal users with a CSV, the CSV generated for your to download has bad invitation links if you're hosting LiteLLM in a sub-directory. It doesn't add the sub-directory to the URL in the invitation link.

### Steps to Reproduce

**PRE-REQUISITE** - you have installed LiteLLM in a sub-path, e.g. https://www.acme.com/litellm

1. Go to Internal Users, Bulk Invite Users, upload a CSV file with email and role 2. After import download the generated CSV with user details within 3. Check `invitation_link`, it will be `https://www.acme.com/ui?invitation_id=XXXXXXXXXXXXX`

It *should* be `https://www.acme.com/litellm/ui?invitation_id=XXXXXXXXXXXXX`

### Relevant log output

```shell

```

### What part of LiteLLM is this about?

UI Dashboard

### What LiteLLM version are you on ?

v1.87.2

### Twitter / LinkedIn details

https://www.linkedin.com/in/gregharvey/