alpha-lambda | Tiny wrapper that ensures that AWS Lambda function | Cloud Functions library

Im trying to apply a function onto my list but it returns this error

"non numeric matrix extent error"

here's my code

the error occurs in the last few lines the code works fine up till the end, and because of this, im unable to plot my graphs I've searched online but couldnt find anything that helps, and I cant see what's wrong with the code

trying to create a table to calculate the mean of my data, but sapply won't work, it keeps giving me the error that 'x' must be an array of at least two dimensions

here's my code

So looking at this question here

"Let A = {0.1, 0.5, 1, 2, 5, 10, 100} L = {0.1, 0.5, 1, 2, 5, 10, 100}

1. For each pair (α, λ) ∈ A × L above, use the built-in R function rgamma() to generate samples of size 10, 000 each from the Gamma(α, λ) distribution. (Do not include your sample in the output!) This will give you 7 × 7 = 49 random samples of size 10, 000 each. These are your datasets you will base the rest of the assignment on.
2. Use the function hist() to plot histograms of your sample datasets. I want 49 histogram. If you can arrange them into a nice 7-by-7 grid, all the better. Clearly label your plots. Remember to play around with the breaks options and choose an appropriate number of bins so that your plots have nicely defined shapes."

Im trying for Q2 and would like to know what Im doing wrong here and even is my Q 1 right