encounter error while running build script

[Taction]

After run cargo +nightly build --target=wasm32-unknown-unknown --release, I get the following output:

Updating `ustc` index
   Compiling version_check v0.9.3
   Compiling log v0.4.14
   Compiling cfg-if v1.0.0
   Compiling primes v0.3.0
error[E0463]: can't find crate for `core`
  |
  = note: the `wasm32-unknown-unknown` target may not be installed
  = help: consider downloading the target with `rustup target add wasm32-unknown-unknown`
  = help: consider building the standard library from source with `cargo build -Zbuild-std`

For more information about this error, try `rustc --explain E0463`.
error: could not compile `cfg-if` due to previous error
warning: build failed, waiting for other jobs to finish...
error[E0463]: can't find crate for `std`
  |
  = note: the `wasm32-unknown-unknown` target may not be installed
  = help: consider downloading the target with `rustup target add wasm32-unknown-unknown`
  = help: consider building the standard library from source with `cargo build -Zbuild-std`

error: build failed

I have run rustup target add wasm32-unknown-unknown but nothing changed.
I am new to rust, does anyone know the reason for this and how to solve it? Any help will be appreciated.