The normalized probability density distribution of Ω _b from 22 localized FRBs. The best fit is ﹩{{\rm{\Omega }}}_{b}={0.0490}_{-0.0033}^{+0.0036}﹩ in 1σ confidence level. The red solid line shows the best-fit value, and dotted lines present the 1σ and 2σ confidence levels. The blue shaded region shows the constraint on Ω _b from cosmic microwave background (CMB) with 1σ confidence level, and the yellow shade region represents the constraint from Big Bang nucleosynthesis (BBN) with 1σ confidence level. The green dashed lines correspond to the 1σ uncertainty range of Ω _b derived by Macquart et al. (2020).