OET interlinear LEV 27:27

uW Translation Notes:

Note 1 topic: translate-fraction

חֲמִשִׁת֖⁠וֹ

(Some words not found in UHB: and=if among,livestock (the),unclean and,he_will_redeem_[it] by,valuation_of,your and,he_will_add its_of,fifth on/upon/above=him/it and=if not redeemed and,it_will_be_sold by,valuation_of,your )

See how you translated this in 27:13

Note 2 topic: figures-of-speech / activepassive

וְ⁠אִם־לֹ֥א יִגָּאֵ֖ל וְ⁠נִמְכַּ֥ר בְּ⁠עֶרְכֶּֽ⁠ךָ

and=if not (Some words not found in UHB: and=if among,livestock (the),unclean and,he_will_redeem_[it] by,valuation_of,your and,he_will_add its_of,fifth on/upon/above=him/it and=if not redeemed and,it_will_be_sold by,valuation_of,your )

The phrase if it is not redeemed, then it shall be sold is a passive verbal form. If your language would not use that form, you could express the idea in active form or in another way that is natural in your language. Alternate translation: [And if no one redeems it, then you must sell it at the value you determined]