im trying to put 3 linear regression results into one graph uing:

equation1=function(x){coef(m1)[2]*x+coef(m1)[1]}
equation2=function(x){coef(m2)[2]*x+coef(m2)[1]+coef(m1)[3]}
equation3=function(x){coef(m3)[2]*x+coef(m3)[1]+coef(m1)[3]+coef(m3)[3]}


ggplot(Behaviour,aes(y=Height,x=Probes,color=Species))+geom_point()+stat_smooth(method="lm", se=FALSE)+xlab("Probes")+ylab("Shore Height")

        ggplot(stat_function(fun=equation1,geom="line",color=scales::hue_pal()(2)[1]))+
       ggplot(stat_function(fun=equation2,geom="line",color=scales::hue_pal()(2)[2]))+
        ggplot(stat_function(fun=equation3,geom="line",color=scales::hue_pal()(2)[3]))

however i keep getting this error:

Error in fortify():
! data must be a <data.frame>, or an object coercible by fortify(), or a valid <data.frame>-like object coercible by as.data.frame().
Caused by error in .prevalidate_data_frame_like_object():
! dim(data) must return an of length 2.
Backtrace:

1. ggplot2::ggplot(…)
2. ggplot2:::ggplot.default(…)
3. ggplot2:::fortify.default(data, …)
4. ggplot2:::validate_as_data_frame(model)
5. ggplot2:::.prevalidate_data_frame_like_object(data)
   Error in fortify(data, …) :
   Caused by error in .prevalidate_data_frame_like_object():
   ! dim(data) must return an of length 2.

im expecting a scatterplot, colour coded for the 3 species mentioned in the code including the lines for linear regression.