A reproducible example, called a reprex is really helpful in avoiding assumptions. Here, I have to assume you mean car::leveragePlots.
The example from the help page produces
library(car)
#> Loading required package: carData
leveragePlots(lm(prestige~(income+education)*type, data=Duncan))
Created on 2019-12-27 by the reprex package (v0.3.0)
But when we reduce the argument to
model1 <- lm(prestige~(income+education)*type, data=Duncan))
leveragePlots(model1 ~ prestige)
Error in eval(predvars, data, env) : object 'prestige' not found
it throws your error.