How to use DB ConnectionString per Logged in user in Asp.Dot Net Core 2.2, JWT

I have two DBContexts in my web API app. 1st one is to have all my client's details with their connestionstring and 2nd one is real DB app.

Login controler use MyClientContext & other all controllers use MyContext

My startup.cs looks

public void ConfigureServices(IServiceCollection services)
        {
            services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2)

            services.AddDbContext<MyContext>(options =>
                    options.UseNpgsql(Configuration.GetConnectionString("MyContext")));

            services.AddDbContext<MyClientContext>(options =>
                    options.UseNpgsql(Configuration.GetConnectionString("MyClientContext")));
        }

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
        {
            using (var serviceScope = app.ApplicationServices.GetService<IServiceScopeFactory>().CreateScope())
            {
                var context = serviceScope.ServiceProvider.GetRequiredService<MyContext>();
                context.Database.Migrate(); // Code First Migrations for App DB

                var context2 = serviceScope.ServiceProvider.GetRequiredService<MyClientContext>();
                context2.Database.Migrate(); // Code First Migrations for Clients DB
            }

            app.UseCors("AllowSpecificOrigin");
            app.UseAuthentication();
            app.UseHttpsRedirection();
            app.UseMvc();
        }

On Login success, I issue JWT Token that looks

private string GenerateJSONWebToken(UserAuth userInfo)
        {
            var securityKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(_config["Jwt:Key"]));
            var credentials = new SigningCredentials(securityKey, SecurityAlgorithms.HmacSha256);

            var claims = new[] {
                new Claim(JwtRegisteredClaimNames.Sub, userInfo.UserName),
                new Claim(JwtRegisteredClaimNames.Email, userInfo.Email),
                new Claim(JwtRegisteredClaimNames.Jti, Guid.NewGuid().ToString())
            };
            var token = new JwtSecurityToken(_config["Jwt:Issuer"], _config["Jwt:Issuer"], claims,
              expires: DateTime.Now.AddHours(24), signingCredentials: credentials);

            return new JwtSecurityTokenHandler().WriteToken(token);
        }

All my controllers have DI. How do I resolve this.