If you are asking how to reclaim SSP, I am afraid that this is no longer possible.
You can take a look at this extract from the HMRC website for more information.
If your question is regarding something else
Resolution for 'covering SS.P. issue: 'how do I claim my company inland revenue tax allowance for covering S.S.P.' available: Yes.
The covering SS.P. issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the covering SS.P. issue yourself by looking for a resolution described in the article. If it is a complex covering SS.P. issue or you are unable to solve the issue, you may contact us by clicking here or by using other covering SS.P. support options.
For more information about resolving issues related to covering SS.P. in Quickbooks/QBO or to get support for the issue 'how do I claim my company inland revenue tax allowance for covering S.S.P.', click the link below: