This detail cannot be added now in GSTR 1. However this is not correct that recipient cannot take the credit. You just please confirm that whether you have paid the taxes through GSTR 3B. If yes then counter party can take the ITC. As we all knows that ITC can be taken if recipient fulfill 4 conditions as laid down in Section 16(2).
(a) he is in possession of a tax invoice or debit note issued by a supplier registered under this Act, or such other tax paying documents as may be prescribed;
(b) he has received the goods or services or both.
(c) subject to the provisions of section 41, the tax charged in respect of such supply has been actually paid to the Government, either in cash or through utilization of input tax credit admissible in respect of the said supply; and
(d) he has furnished the return under section 39:
Please note that there is no condition that transaction should appear in GSTR 2A. This condition has now added vide Rule 36(4) of CGST Act w.e.f. 9th ct 2019.
One more point if the taxes has not been paid through GSTR 3B then the same can be paid through DRC-03.
Regards
Arun Chhajer
Swastika Educonsult Pvt ltd