the manifest is missing a Swift tools version specification; consider prepending to the manifest '// swift-tools-version: 5.7.1' to specify the current Swift toolchain version as the lowest Swift version supported by the project; if such a specification already exists, consider moving it to the top of the manifest, or prepending it with '//' to help Swift Package Manager find it
After adding dependency, the following error:
the manifest is missing a Swift tools version specification; consider prepending to the manifest '// swift-tools-version: 5.7.1' to specify the current Swift toolchain version as the lowest Swift version supported by the project; if such a specification already exists, consider moving it to the top of the manifest, or prepending it with '//' to help Swift Package Manager find it