alpine-mirrors apk is missing in 3.13.x
No alpine-mirrors apk in 3.13.x distribution, setup-apkrepos has nothing to choose from. Normal install from scratch is not possible.
Manual correction is possible, but requires a prior version of Alpine handy.
# setup-apkrepos wget: error getting response wget: error getting response r) Add random from the above list f) Detect and add fastest mirror from above list e) Edit /etc/apk/repositories with text editor Enter mirror number (1-0) or URL to add (or r/f/e/done)  f Finding fastest mirror... Warning! No mirror found
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information