Yes, the IRS discontinued e-fileing extensions on May 17. If you mail file be sure to mail certified so you have proof of mailing before midnight tomorrow (6/15).
https://www.irs.gov/pub/irs-pdf/f4868.pdf
Remember, an extension is only to file, not to pay. Any tax owed must be paid by 6/15 and if you are getting a refund, there is no penalty for filing late.
I'm in Texas and I just e-filed my return. Turbo Tax allowed me to do so and I have not received any notice of a rejection from TT or the IRS.
@MikeInPlano Are you referring to e-filing your tax return or e-filing a request for an extension? It does make a difference. You can e-file your 2020 tax return. You cannot e-file a request for an extension now.