No, no, no, Proxar is the name of the Carl Zeiss made close-up lenses.
This is how it is:
For Rolleiflex in the 30's and 40's Zeiss made the Proxar close-up lenses. The came in sets in these mounts:
1 x 24 mm and 1 x 28,5 mm push-on for the Original Rolleiflex.
2 x 28,5 mm push-on for the Rolleiflex Standard, early Rolleicords without bayonets, and they can also be used on the Rolleicord II type 2 - type 6, and the early Rolleiflex Automats, since they can accept push-on accessories.
1 x 28,5 mm push-on and 1 x Bayonet 1, for the 1937-38 Rolleiflex Automat and Rolleicord II type 2 and 3, with bayonet on the taking lens only.
2 x Bayonet 1, for the 1939 Rolleiflex Automat and later, and the Rolleicord II, type 4 and later.
For these sets you could buy the parallax compensating prism Rolleipar/Rolleiparkeil to be used on the viewing lens.
From 1950 the close-up lenses were made by F&H under their own tradename Rolleinar, and came in bayonet mounts. First in three-piece sets, the lenses plus the Rolleiparkeil parallax compensation prism, and later in two-piece sets with the prism anc lens in one unit for the viewing lens.
What you want is either the Proxars in 2 x 28,5 mm push-on, or better, the set with 1 x 28,5 mm push-on and 1 x Bayonet 1, plus the Rolleipar in 28,5 mm push-on mount.
But bear in mind that close-up lenses give the lens a wider angle and can distort the face a bit, like giving the person photographed a bigger nose. (The Proxar was also sold as a simple wide angle accessory lens for large format cameras, and the Distar minus lens as a simple "tele" accessory lens). You can shoot portraits without Proxar/Rolleinar and crop during printing instead, if you don't really need to fill the whole negative.