Currently The Department of Education is not accepting new digital consolidation applications while it is reviewing the latest lawsuit against the SAVE plan. Paper applications will be accepted. If you would like to go ahead and submit a paper application, you can follow the steps in this article.
If you have other federal loans (such as FFEL loans), you can consolidate them into a Direct Consolidation Loan which qualify. The one exception is FFEL Joint/Spousal Consolidation loans cannot be consolidated into a Direct Consolidation Loan.
As for how it affects PSLF, according to Federal Student Aid Office, you will receive a weighted average of qualifying payments on your Direct Consolidation Loan to be counted toward the 120 payments required for the program.
In order to consolidate your loans into a qualifying Direct Consolidation Loan, you may submit a consolidation application online after logging in to your Federal Student Aid account. Read more about Direct Consolidation Loans here.