to section 1434(j) of the BUILD Act of 2018 may remain available for obligation for 1 additional fiscal year: Provided further , That the total loan principal or guaranteed principal amount shall not exceed $8,000,000,000. Trade and development agency For necessary expenses to carry out the provisions of section 661 of the Foreign Assistance Act of 1961, $79,500,000, to remain available until September 30, 2022, of which no more than $18,285,000 may be used for administrative expenses: Provided , That of the funds appropriated under this heading, not more than $5,000 may be available for representation and entertainment expenses. VII General provisions Allowances and differentials 7001. Funds appropriated under title I of this Act shall be available, except as otherwise provided, for allowances and differentials as authorized by sub chapter 59 of title 5, United States Code