The Constitution of Belarus originally adopted in 1994 including Section II outlines the protected freedom of expression in Article 33.

References:

1994 Constitution of the Republic of Belarus: https://heinonline-org.proxygw.wrlc.org/HOL/Page?collection=cow&handle=hein.cow/zzby0006&id=4&men_tab=srchresults

1994 Constitution of the Republic of Belarus as amended in 1996: https://www.venice.coe.int/webforms/documents/?pdf=CDL(2003)065-e