Hi @rschuntigit,
You can update a key using this syntax.
curl --request PUT --fail --silent --show-error "http://localhost:8500/v1/kv/a/b/c?token=<token>" --data 'nnn'
The value can then be retrieved and stored in a variable using this command.
export VARIABLE=$(curl --fail --silent --show-error "http://localhost:8500/v1/kv/a/b/c?token=<token>&raw")
See https://www.consul.io/api-docs/kv for more info on the supported arguments for these API calls.