Hello,
Currently, Apple does not have a way to manually enter in results into the Apple Health App if it is not an already provided metric. You can try adding the Provider of your Lipid Panel as a workaround by going to the Health App >> Your Profile >> Health Records >> Add Account, and searching by the Hospital or Network that provided the care. You can reference the following article: View health records on your iPhone or iPod touch - Apple Support.
To suggest this feature, you can go to Product Feedback - Apple, click on Health under the iOS and iPadOS apps, change the feedback type to feature request, and add your personal information and comments. Hope this helps.
Yasamean