I found solution. Maybe it will be helpful for somebody:

const tempFilePath = './storage/saved2' // tempFile - file generated by daemon-cli

const payload = await fsPromise.readFile(tempFilePath, {encoding: 'base64'});
        
const payloadBase64 = Cell.fromBase64(payload)

await provider.internal(via, {
    value: "0.5",
    body: payloadBase64
});

I found solution. Maybe it will be helpful for somebody.

I send message using ton-core js sdk:

const tempFilePath = './storage/saved2' // tempFile - file generated by daemon-cli

const payload = await fsPromise.readFile(tempFilePath, {encoding: 'base64'});
        
const payloadBase64 = Cell.fromBase64(payload)

await provider.internal(via, {
    value: "0.5",
    body: payloadBase64
});