I was having trouble getting Interact.jl to work, you know, interactively in a Jupyter notebook. I finally found that the problem is that I was using StatsPlots.jl and not Plots.jl. I was not actually using any of the functionality specific to StatsPlots. Since StatsPlots reexports Plots, is there a particular reason why this should not work?
using Interact, Distributions, StatsPlots
@manipulate for α in 1:100, β = 1:100
plot(x -> pdf(Beta(α, β), x), 0, 1)
end