buildx to arm build command

.github/workflows/main.yml

@@ -106,7 +106,7 @@ jobs:
           [ -z "$SOFTETHER_VERSION" ] && { echo "Softether version not defined"; exit 1; }
           echo -e "\n\nDockerfile:\n$( cat Dockerfile )\n\n"
 
-          docker build --rm --platform linux/arm64 -t croc/softether-arm64 . || { echo "Docker image build fail - ARM64"; exit 1; }
+          docker buildx build --rm --platform linux/arm64 -t croc/softether-arm64 . || { echo "Docker image build fail - ARM64"; exit 1; }
           docker tag croc/softether-arm64 croc/softether-arm64:$SOFTETHER_VERSION
       - name: push container
         env: