demo:

async function getClient() {
    return await {
        call: (data) => {console.log('call', data)}
    };
}

async function test(data: string) {
    const client = await getClient();
    await client?.call(data);
    return true;
}
test("1");

tsup.config.json

import {defineConfig} from 'tsup';

process.env.NODE_ENV = 'development';


export default defineConfig([
    {
        entry: ['./index.ts'],
        format: ['cjs'],
        splitting: true,
        sourcemap: true,
        minify: true,
        outDir: './dist/',
        noExternal: [],
        define: {
        },
        plugins: [
        ],
        target: 'es2020',
        tsconfig: './tsconfig.json'
    }
]);

tsconfig.json

{
    "compilerOptions": {
        "types": ["node"],
        "target": "ES2022",
        "paths": {
        },
        "typeRoots": [
        ]
    },
    "include": [
    ],
    "exclude": ["node_modules"]
}

run dist/index.js

the error:

"use strict"; async function _asyncOptionalChain(ops) { let lastAccessLHS = undefined; let value = ops[0]; let i = 1; while (i < ops.length) { const op = ops[i]; const fn = ops[i + 1]; i += 2; if ((op === 'optionalAccess' || op === 'optionalCall') && value == null) { return undefined; } if (op === 'access' || op === 'optionalAccess') { lastAccessLHS = value; value = await fn(value); } else if (op === 'call' || op === 'optionalCall') { value = await fn((...args) => value.call(lastAccessLHS, ...args)); lastAccessLHS = undefined; } } return value; }async function n(){return await{call:t=>{console.log("call",t)}}}async function a(t){return awaitawait _asyncOptionalChain([(await n()), 'optionalAccess', async _ => _.call, 'call', async _2 => _2(t)]),!0}a("1");
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               ^^^^^^^^^^^^^^^^^^^

SyntaxError: Unexpected identifier
    at internalCompileFunction (node:internal/vm:73:18)
    at wrapSafe (node:internal/modules/cjs/loader:1178:20)
    at Module._compile (node:internal/modules/cjs/loader:1220:27)
    at Module._extensions..js (node:internal/modules/cjs/loader:1310:10)
    at Module.load (node:internal/modules/cjs/loader:1119:32)
    at Module._load (node:internal/modules/cjs/loader:960:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:86:12)
    at node:internal/main/run_main_module:23:47