How to allow .bin files upload?

This code would allow you to upload .bin files.

/**
 * Allow upload bin mime type
 */
add_filter( 'upload_mimes', 'wpse_287673_allow_upload_bin_mime_type', 1, 1 );

function wpse_287673_allow_upload_bin_mime_type( $mime_types ) {

  $mime_types['bin'] = 'application/octet-stream';

  return $mime_types;
}

This code is tested and is working for me, but it might be some differences for you since we are allowing files to be uploaded by extension and mime type and mime type of your file is defined by webserver.