It's impossible to connect wallet using wallet connect if I use the dApp from mobile device. Only modal window with QR code is appeared, but I can't scan QR code with the same mobile device, so user is stuck.

Describe the solution you'd like

I propose you to add the mobileWallet and desktopWallet properties to web3Modal of WalletConnectStore:

interface WalletConnectStore {
    options: SignClientTypes.Options | null;
    web3Modal?: Pick<Web3ModalConfig, "mobileWallets", "desktopWallets", "themeVariables" | "themeMode" | "privacyPolicyUrl" | "termsOfServiceUrl"> | null;
}

Describe alternatives you've considered

Other way is to create walletList property of GrazProvider and map its value to put to WalletConnect, if it's enabled (projectId is defined)