npm start

[joanrs]

at /home/joan/Documentos/unisat wallet/unisat-web3-demo-master/node_modules/babel-loader/lib/index.js:51:103 {

opensslErrorStack: [ 'error:03000086:digital envelope routines::initialization error' ],
library: 'digital envelope routines',
reason: 'unsupported',
code: 'ERR_OSSL_EVP_UNSUPPORTED'

[joanrs]

Solution: on file package.json

replace "start": "react-scripts start" by "start": "react-scripts --openssl-legacy-provider start"
replace "build": "react-scripts build" by "build": "react-scripts --openssl-legacy-provider build"