Who can open an alto crypto IRA?

Could you elaborate on the eligibility criteria for individuals to open an Alto Crypto IRA? I'm interested in understanding the general requirements and qualifications needed to establish such an account. Are there any specific age restrictions, residency requirements, or financial thresholds that need to be met? Additionally, is it only open to U.S. citizens, or are international investors eligible as well? Your clarification on these points would be greatly appreciated.