Reading through Publication 544, I think sending crypto to a scam exchange does not fit under any of these "disposition" of asset
Publication 544 (2022), Sales and Other Dispositions of Assets | Internal Revenue Service (irs.gov)
You dispose of property when any of the following occur.
You sell property.
You exchange property for other property.
Your property is condemned or disposed of under threat of condemnation.
Your property is repossessed.
You abandon property.
You give property away
