If they have Lightroom or Photoshop, send them a DNG. If not, what program will they use to look at your adjustments?
You can select "Original" as the file type, in Export. This saves out a copy of the imported source file into the selected location, labelling the current adjustments onto that image. When this is sent to somebody and imported to LR / opened in ACR, these metadata will be found and used automatically, with the exact same outcome as within your own LR Catalog - provided the LR / ACR versions are sufficiently compatible, and provided camera and lens profiles applied to the image, are present in both contexts.
LR uses whatever method is normal when writing metadata, for each file type involved. So, if one imported file is a proprietary Raw file, LR will write an XMP file alongside. If another is capable of having metadata written into its file header, LR will do that instead.
One important difference between doing this, vs writing LR metadata out to your original imported file, and sending that: the Export Original method will work in the same way, just as successfully, for one or more Virtual Copy versions (duplicating physically as needed), as it will for the primary Master version - relating to a given imported file.
Thank you, these answers help.