Xubuntu 18.04.3-32bit - Child process failed on executing bash

To make it easier to install a new kernel, I created the following bash:

Code: Kernel installation:
**********************

read -p "Please input kernel number: `echo '\n> '`" a
sleep 1
echo

sudo apt install linux-headers-"${a}" linux-headers-"${a}"-generic linux-image-"${a}"-generic linux-modules-"${a}"-generic linux-modules-extra-"${a}"-generic
sleep 2
echo

read -p "Hit Enter key to close ... " EnterExecution of this script is granted, but still it doesn't work.

There's a message telling me
Code:Child process failed!
Child process cannot be executed. No privilegeHow come and what can I do about it, please?