Response code 400 when trying to set scale-in protection

I want to to set scale-in protection as explained here via a PUT request to $ECS_AGENT_URI/task-protection/v1/state.

However, I always get the following error: Response code 400 (Bad Request) .

This is my code:

const got = require("got");

const SCALE_IN_PROTECTION_DURATION_MINUTES = 15;
const TASK_PROTECTION_URI = `${process.env.ECS_AGENT_URI}/task-protection/v1/state`;
try {
  const minutes = SCALE_IN_PROTECTION_DURATION_MINUTES;
  await got(TASK_PROTECTION_URI, {
    method: "PUT",
    json: { ProtectionEnabled: true, ExpiresInMinutes: minutes },
  });
} catch (error) {
  logger.error(error);
}

process.env.ECS_AGENT_URI is set properly and the instance agent version is 1.70.0