Hi Anna,
It’s worthy to check if the employer is a related party of the SMSF.
There is a related party exemption to receive contributios via Superstream. See below extracted from: https://www.ato.gov.au/businesses-and-organisations/super-for-employers/paying-electronically-through-superstream/self-managed-super-funds/examples-smsfs-and-superstream
Example 2: SMSF receives contributions only from family business
SuperSavings SMSF has been established for your family, and all members of the SMSF are either owners or employees of the family business. No members receive contributions from other employers.
Because of the direct link between ownership of the family business and membership of the SMSF, the SMSF meets the related party exemption. This means the SMSF doesn’t need to receive contributions sent using SuperStream.
Your family business also has other employees who belong to other super funds. Your business will need to use SuperStream to send employer contributions to their funds.