We need to switch from bond-backed money to UBI-backed money or cryptocurrency (or both). Hereby I explain how UBI-backed money would work:

  How money flows
  - UBI is no-strings attached and provided from both fresh* and recycled money
  - Taxes continue as usual
  - Monetary supply is controlled by amount of government wages and UBI. Demand is controlled by amount of taxes.
  Assumptions
  - Everyone except civil servants get equal amount of BI
  - civil servants get a wage which is greater than or equal to BI instead
  * as in, UBI itself is an instrument to print money, this also applies to civil servant wages

No interest needed in this scheme. Just three variables: number of citizens, amount of UBI and civil servant wages, amount of taxes. UBI is provided from both fresh and recycled money, if we otherwise provided it only from fresh money, inflation would arise. Or the opposite, only recycled money would still require bond-backed money as civil servant wages are not enough of monetary supply for all the citizens.