Those shifters are for very old bikes or maybe some kids bikes. 22.8mm (7/8 in) - your bars are probably 1inch and maybe 1.25 inch where they meet the stem.
Saw an Amazon ad that said “will fit most bikes”. Absolute BS.
edit: although
this site claims the Revoshift shifters are also for 7/8in bars. Interesting.
Shimano don’t specify. Have you measured your bars?