ipcmain.handle parameter has metadata(?) instead of value

I am a beginner to electron and my app does nothing more than unpack a zip and start a .bat file (it’s an installer) i need the user to give a url to a database but when it returns i get in ipcMain: {"sender":{"_windowOpenHandler":null,"ipc":{"_events":{},"_eventsCount":1,"_invokeHandlers":{}},"_events":{"render-process-gone":[null,null]},"_eventsCount":13},"frameId":1,"processId":4}

main.js: (not entire file just handle)

    ipcMain.handle('run-start', async (database) => {
        console.log(`dbUrl in main.js:`, JSON.stringify(database), `Type:`, typeof database);
    const command = path.join(filePath, 'dist', 'setup.bat') + ' ' + database
    try {
        console.log(command)
        // const result = await new Promise((resolve, reject) => {
        //     exec(command, (error, stdout, stderr) => {
        //         if (error) {
        //             reject(`Error: ${stderr}`);
        //         } else {
        //             resolve(stdout);
        //         }
        //     });
        // });
        return result;
    } catch (error) {
        return error;
    }
})

preload.js (entire file):

const { contextBridge, ipcRenderer } = require('electron');

contextBridge.exposeInMainWorld('electron', {
    selectFolder: () => ipcRenderer.invoke('select-folder'),
    runInstall: (destDir) => ipcRenderer.invoke('run-install', destDir),
    runStart: (dbUrl) => {ipcRenderer.invoke('run-start', dbUrl); console.log(dbUrl)}
});

index.html (just the handler for the clicked btn):

        document.getElementById('startButton').addEventListener('click', async () => {
        console.log(dbUrl)
        await window.electron.runStart(dbUrl)
        alert('ClassyBooks is gestart!');
    });

everywhere the dbUrl is correct except in main.js