Upgrade of awk/sed commands inside busybox container

Hello team,

I request you a support here,
I am using docker hub which has a busybox container 1.31v. in Linux machine.
The basic sed commands(eg: Lowercase to Uppercase) are not working the default versions of awk and sed

Example: When i try this basic sed Lower case to Capital case command, the output has some extra character for every line/word

sed -e “s/{.*}/\U&/”.

How can we upgrade the awk/sed commands in busybox container?

Please let me know.