@mon thank you for following up! I have edited your response and removed the link to your file to protect your privacy.
For context, Lucid does not support the import of files with the .INDD format. Please go through our Import files into Lucidchart and Import files into Lucidspark Help Center articles for a detailed overview of file formats supported by Lucid and various alternatives to import them.
Regarding PDF files, you can drag and drop the PDF file into your Lucidchart document, or use Insert > PDF. This will bring the PDF into Lucidchart as an embedded link with the first page of the PDF becoming the default thumbnail.
Alternatively, you can import your InDesign files into Lucid with the .JPEG and .PNG formats through Insert > Image.
If issues persist, could you please provide screenshots illustrating the steps taken and the issue being experienced?
We’re very interested in your feedback and committed to continually improving our products. Please first search the Product Feedback section of this community (with the filter Topic Type = Idea) to see if it’s already been submitted. If so, please add any additional details you’d like and upvote the request - this consolidation helps to refine feedback and properly capture the popularity of the request.
If no one has submitted this idea yet, please create one of your own and be sure to include details about your use case or what you’d like to see in this experience. This will also allow other users with similar requests to discover and upvote it, then add details of their own.
Finally, for more information on how Lucid manages feedback via this community, take a look at this post:
Cheers!