Move the .wasm file to src/assets The simplest way is to copy the matrix_sdk_crypto_wasm_bg.wasm file from node_modules/@matrix-org/matrix-sdk-crypto-wasm/pkg/ into your Angular src/assets/ directory.

For example: cp node_modules/@matrix-org/matrix-sdk-crypto-wasm/pkg/matrix_sdk_crypto_wasm_bg.wasm src/assets/