We investigate a single field model in the context of the constant-roll inflation in which inflaton moves down to the minimum point of the potential with a constant rate of rolling. We use a quintessential inflationary model obtained by a Lorentzian function which is dependent on the number of e-folds. We present the inflationary analysis for the model and find the observational constraints on the parameters space using the observations of CMB anisotropies i.e. the Planck and Keck/array datasets. We find the observationally acceptable values of the Width of the Lorentzian function as 0.3 < Γ ≤ 0.5 at the 68% CL and Γ ≤ 0.3 at the 95% CL when ξ = 120, |β| = 0.02 and N = 60. Also, we acquire the observationally favoured values of the amplitude of the Lorentzian function as 400 < ξ ≤ 600 at the 68% CL and ξ ≤ 400 at the 95% CL when Γ = 0.1, |β| = 0.02 and N = 60. Moreover, we study the model from the Weak Gravity Conjecture approach using the swampland criteria.
